Answer: 60
Step-by-step explanation:
Given : The number of choices for different temperatures = 3
The number of choices for different pressures = 4
The number of choices for different catalyst = 5
Since , the experimenter is studying the effects of temperature, pressure, and different type of catalysts.
Then by using the Fundamental principle of counting , we have
The number of experimental runs are available = (number of choices for temperatures ) x (number of choices for pressures) x( number of choices for catalyst)
= 3 x 4 x 5 = 60
Hence, the number of experimental runs are available = 60
The heights of apricot trees in an orchard are approximated by a normal distribution model with a mean of 18 feet and a standard deviation of 1 feet. What is the probability that the height of a tree is between 16 and 20 feet
Answer:
0.9544
Step-by-step explanation:
We are given that mean=18 and standard deviation=1 and we have to find P(16<X<20).
P(16<X<20)=P(z1<Z<z2)
z1=(x1-mean)/standard deviation
z1=(16-18)/1=-2
z2=(x2-mean)/standard deviation
z2=(20-18)/1=2
P(16<X<20)=P(z1<Z<z2)=P(-2<Z<2)
P(16<X<20)=P(-2<Z<0)+P(0<Z<2)
P(16<X<20)=0.4772+0.4772=0.9544
The probability that the height of a tree is between 16 and 20 feet is 95.44%
According to a posting on a website subsequent to the death of a child who bit into a peanut, a certain study found that 7% of children younger than 18 in the United States have at least one food allergy. Among those with food allergies, about 41% had a history of severe reaction.a. If a child younger than 18 is randomly selected, what is the probability that he or she has at least one food allergy and a history of severe reaction? (Enter your answer to four decimal places.) b. It was also reported that 30% of those with an allergy in fact are allergic to multiple foods. If a child younger than 18 is randomly selected, what is the probability that he or she is allergic to multiple foods? (Enter your answer to three decimal places.)
a) The probability that he or she has at least one food allergy and a history of severe reaction is 0.0287.
b) The probability that he or she is allergic to multiple foods is, 0.021
Given that;
A certain study found that 7% of children younger than 18 in the United States have at least one food allergy.
a. Since the probability that a child younger than 18 has at least one food allergy is given as 7%.
Among those with food allergies, the probability of having a history of severe reaction is 41%.
Hence for the probability that a child has both at least one food allergy and a history of severe reaction, multiply these probabilities together:
7% × 41% = 0.07 × 0.41
= 0.0287.
Therefore, the probability is 0.0287.
b) For the probability that a randomly selected child younger than 18 is allergic to multiple foods, consider the information given.
The probability of having at least one food allergy among children younger than 18 is 7%.
And among those with allergies, 30% are allergic to multiple foods.
Hence for the probability, multiply the probability of having at least one food allergy (7%) by the probability of being allergic to multiple foods (30% of those with allergies):
Probability = 7% × 30%
= 0.07 × 0.30
= 0.021.
Therefore, the probability that a randomly selected child younger than 18 is allergic to multiple foods is 0.021.
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The probability that a child younger than 18 has at least one food allergy and a history of severe reaction is approximately 0.029. The probability that a child younger than 18 is allergic to multiple foods is approximately 0.021.
Explanation:To find the probability that a child younger than 18 has at least one food allergy and a history of severe reaction, we can use the information provided. We know that 7% of children younger than 18 have at least one food allergy and among those with food allergies, 41% had a history of severe reaction. To calculate the probability, we multiply these two probabilities together: 0.07 (the probability of having a food allergy) multiplied by 0.41 (the probability of having a severe reaction given a food allergy). So, the probability is 0.07 * 0.41 = 0.0287, which can be rounded to 0.0287 or approximately 0.029.
To find the probability that a child younger than 18 is allergic to multiple foods, we use the information that 30% of those with an allergy are allergic to multiple foods. So, the probability is 0.07 (the probability of having a food allergy) multiplied by 0.30 (the probability of being allergic to multiple foods given a food allergy). Hence, the probability is 0.07 * 0.30 = 0.021, which can be rounded to 0.021 or approximately 0.021.
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The curve given by:
x=sin(????); y=sin(????+sin(????))
has two tangent lines at the point (x,y)=(0,0).
List both of them in order of increasing slope. Your answers should be in the form of y=????(x) without ????′????.
Answer:
Equations of tangent lines are
y= 2 x
y = 0
Step-by-step explanation:
x = sin t -- (1)
y = sin(t + sin(t)) -- (2)
Differentiating both equations w.r.to t to find slopes.
[tex]\frac{dx}{dt}=\frac{d(sin(t))}{dt}\\\\\frac{dx}{dt}=cos(t)--(3)[/tex]
[tex]\frac{dy}{dt}=\frac{d}{dt}(sin(t+sin(t))\\\\\frac{dy}{dt}=cos(t+sin(t))\frac{d}{dt}(t+sin(t))\\\\\frac{dy}{dt}=cos(t+sin(t)(1+cos(t))\\\\\frac{dy}{dt}=(1+cos(t))cos(t+sin(t))--(4)[/tex]
Dividing (2) by (1) to find slope
[tex]\frac{dy}{dx}=\frac{(1+cos(t))cos(t+sin(t))}{cos(t)}\\[/tex]
at tangent point x=y=0
From (1)
sin (t) = 0
⇒ t = 0, π
At t = 0
[tex]\frac{dy}{dx}\Big|_{t=0}=\frac{(1+cos(t))cos(t+sin(t))}{cos(t)}\\\\\\\frac{dy}{dx}\Big|_{t=0}=\frac{(1+cos(0))cos(0+sin(0))}{cos(0)}\\\\\\\frac{dy}{dx}\Big|_{t=0}=\frac{(1+1)cos(0+0)}{1}\\\\\\\frac{dy}{dx}\Big|_{t=0}=2\\[/tex]
At t= π
[tex]\frac{dy}{dx}\Big|_{t=\pi}=\frac{(1+cos(t))cos(t+sin(t))}{cos(t)}\\\\\\\frac{dy}{dx}\Big|_{t=\pi}=\frac{(1+cos(\pi))cos(\pi+sin(\pi))}{cos(\pi)}\\\\\\\frac{dy}{dx}\Big|_{t=\pi}=\frac{(1-1)cos(\pi+0)}{-1}\\\\\\\frac{dy}{dx}\Big|_{t=\pi}=0\\[/tex]
Equation of tangent
[tex](y-y_o)=m_t(x-x_o)\\[/tex]
[tex]Tangent\,\,point=(x_o,y_o)=(0,0)\\\\For\,\,t=0\\\\(y-0)=(2)(x-0)\\\\y=2x\\\\for\,\,t=\pi\\\\(y-0)=(0)(x-0)\\\\y=0[/tex]
The list of digits below is from a random number generator using technology. Use the list of numbers to obtain a simple random sample of size 3 from this list. If you start on the left and take the first three numbers between 1 and 9, what three books would be selected from the numbered list?
Question Continuation
5 2 5 5 2 1 0 5 7 5 8 9 3 7 2
Options
A. A Tale of Two Cities, Huckleberry Finn, A Tale of Two Cities
B. A Tale of Two Cities, Huckleberry Finn, The Sun Also Rises
C. A Tale of Two Cities, Huckleberry Finn, Crime and Punishment
D. Huckleberry Finn, Crime and Punishment, The Jungle
E. Crime and Punishment, The Jungle, The Sun Also Rises
Book List
1. Crime and Punishment
2. Huckleberry Finn
3. The Sun Also Rises
4. As I Lay Dying
5. A Tale of Two Cities
6. Death of a Salesman
7. The Jungle
8. Pride and Prejudice
9. The Scarlet Letter
Answer:
C. A Tale of Two Cities, Huckleberry Finn, Crime and Punishment
Step by step explanation
Counting from the left, the selected numbers are 5 , 2 and 1
The books are
5. A Tale of two cities
2. Huckleberry Finn
1. Crime and Punishment
Note that the numbers on the list are 5 2 5 5 2 1
After book 5 and 2 have been selected, the next series of numbers (5 5 2) can not be considered because they've already been selected.
So, the next number after 5 2 5 5 2 is then selected, which is 1
The selected books are:
The books are: A Tale of two cities, Huckleberry Finn, Crime and Punishment
The simple random selection of three books using the random number generated will include the books : The Sun also rises, The Scarlet letter, Crime and Punishment.
The random number generated using technology include :
7, 2, 7, 2, 2, 6, 7, 0, 8, 3, 2, 8, 5, 3, 1
Making a selection of 3 numbers between (1 - 9) starting from the left hand side of the list : 7, 2, 6 ( repeated numbers are only chosen once) as we have to make a unique selection of numbers.From the list of number books attached below :
7. The Sun also rise
2. The Scarlet letter
6. Crime and Punishment
Hence, the randomly selected books will be :
The Sun also rises, The Scarlet letter, Crime and Punishment.
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A perpetuity pays $50 per year and interest rates are 9 percent. How much would its value change if interest rates decreased to 6 percent?
Answer:
We conclude that its value change for 277.8$.
Step-by-step explanation:
We know that a perpetuity pays $50 per year and interest rates are 9 percent. We calculate how much would its value change if interest rates decreased to 6 percent. We know that
9%=0.09
6%=0.06
We get
\frac{50}{0.09}=555.5
\frac{50}{0.06}=833.3
Therefore, we get 833.3-555.5=277.8
We conclude that its value change for 277.8$.
The value change for $277.8.
The calculation is as follows:
[tex]\frac{50}{0.09}=555.5\\\\\frac{50}{0.06}=833.3[/tex]
So,
= $833.3 - $555.5
= $277.8
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The amount of corn chips dispensed into a 10-ounce bag by the dispensing machine has been identified at possessing a normal distribution with a mean of 10.5 ounces and a standard deviation of 0.2 ounces (these are the population parameters). Suppose a sample of 100 bags of chips were randomly selected from this dispensing machine. Find the probability that the sample mean weight of these 100 bags is less than 10.45 ounces. (Hint: think of this in terms of a sampling distribution with sample size
Answer:
0.62% probability that the sample mean weight of these 100 bags is less than 10.45 ounces.
Step-by-step explanation:
To solve this question, the concepts of the normal probability distribution and the central limit theorem are important.
Normal probability distribution
Problems of normally distributed samples can be solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Central Limit Theorem
The Central Limit Theorem estabilishes that, for a random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], a large sample size can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\frac{\sigma}{\sqrt{n}}[/tex]
In this problem, we have that:
[tex]\mu = 10.5, \sigma = 0.2, n = 100, s = \frac{0.2}{\sqrt{100}} = 0.02[/tex]
Find the probability that the sample mean weight of these 100 bags is less than 10.45 ounces
This is the pvalue of Z when X = 10.45. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{10.45 - 10.5}{0.02}[/tex]
[tex]Z = -2.5[/tex]
[tex]Z = -2.5[/tex] has a pvalue of 0.0062.
So there is a 0.62% probability that the sample mean weight of these 100 bags is less than 10.45 ounces.
The probability of the sample mean weight being less than 10.45 ounces can be found by calculating the Z-score and referencing a standard normal distribution table. The calculated Z-score (-2.5) corresponds to a probability of approximately 0.62%.
Explanation:The problem is about determining the probability that the sample mean weight of corn chip bags is less than 10.45 ounces. This is a problem of finding a probability in a sampling distribution when the population parameters are known. Given the data, we can use the Central Limit Theorem, which states that if the sample size is large enough (usually >30), the sampling distribution approximates a normal distribution.
To solve this, you can use the formula Z = (X - μ) / (σ/√n), where X is the sample mean, μ is the population mean, σ is the population standard deviation, and n is the sample size.
Plugging in the given values: Z = (10.45 - 10.5) / (0.2 / √100) = -2.5. The Z-score tells us how many standard deviations away our data point is from the mean. To find the probability that the Z is less than -2.5, you can refer to a standard normal distribution table or use statistical software. According to the Z table, the probability is approximately 0.0062 or 0.62% that the sample mean weight of these 100 bags is less than 10.45 ounces.
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The average time entities spend in the system in five simulation runs are: 25.2, 19.7, 23.6, 18.6, and 21.4 minutes, respectively. Five more simulations are run and the following average times in the system are obtained 22.1, 26.0, 20.2, 16.4, and 17.9 minutes. a). Build a 95% confidence interval for the mean time in the system using the first five averages collected.
Answer:
a) [tex]21.7-2.776\frac{2.718}{\sqrt{5}}=18.33[/tex]
[tex]21.7+2.776\frac{2.718}{\sqrt{5}}=25.07[/tex]
So on this case the 95% confidence interval would be given by (18.33;25.07)
b) [tex]20.52-2.776\frac{3.757}{\sqrt{5}}=18.84[/tex]
[tex]20.52+2.776\frac{3.757}{\sqrt{5}}=22.20[/tex]
So on this case the 95% confidence interval would be given by (18.84;22.20)
c) [tex]21.11-2.262\frac{3.154}{\sqrt{10}}=18.85[/tex]
[tex]21.11+2.262\frac{3.154}{\sqrt{10}}=23.37[/tex]
So on this case the 95% confidence interval would be given by (18.85;23.37)
And as we can see the confidence intervals are very similar for the 3 cases.
Step-by-step explanation:
Previous concepts
A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".
The margin of error is the range of values below and above the sample statistic in a confidence interval.
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
[tex]\bar X[/tex] represent the sample mean for the sample
[tex]\mu[/tex] population mean (variable of interest)
s represent the sample standard deviation
n represent the sample size
Part a) Build a 95% confidence interval for the mean time in the system using the first five averages collected.
The confidence interval for the mean is given by the following formula:
[tex]\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}[/tex] (1)
Data: 25.2, 19.7, 23.6, 18.6, and 21.4
In order to calculate the mean and the sample deviation we can use the following formulas:
[tex]\bar X= \sum_{i=1}^n \frac{x_i}{n}[/tex] (2)
[tex]s=\sqrt{\frac{\sum_{i=1}^n (x_i-\bar X)}{n-1}}[/tex] (3)
The mean calculated for this case is [tex]\bar X=21.7[/tex]
The sample deviation calculated [tex]s=2.718[/tex]
In order to calculate the critical value [tex]t_{\alpha/2}[/tex] we need to find first the degrees of freedom, given by:
[tex]df=n-1=5-1=4[/tex]
Since the Confidence is 0.95 or 95%, the value of [tex]\alpha=0.05[/tex] and [tex]\alpha/2 =0.025[/tex], and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,4)".And we see that [tex]t_{\alpha/2}=2.776[/tex]
Now we have everything in order to replace into formula (1):
[tex]21.7-2.776\frac{2.718}{\sqrt{5}}=18.33[/tex]
[tex]21.7+2.776\frac{2.718}{\sqrt{5}}=25.07[/tex]
So on this case the 95% confidence interval would be given by (18.33;25.07)
Part b: Build a 95% confidence interval for the mean time in the system using the second set of five averages collected.
Data: 22.1, 26.0, 20.2, 16.4, and 17.9
The mean calculated for this case is [tex]\bar X=20.52[/tex]
The sample deviation calculated [tex]s=3.757[/tex]
In order to calculate the critical value [tex]t_{\alpha/2}[/tex] we need to find first the degrees of freedom, given by:
[tex]df=n-1=5-1=4[/tex]
Since the Confidence is 0.95 or 95%, the value of [tex]\alpha=0.05[/tex] and [tex]\alpha/2 =0.025[/tex], and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,4)".And we see that [tex]t_{\alpha/2}=2.776[/tex]
Now we have everything in order to replace into formula (1):
[tex]20.52-2.776\frac{3.757}{\sqrt{5}}=18.84[/tex]
[tex]20.52+2.776\frac{3.757}{\sqrt{5}}=22.20[/tex]
So on this case the 95% confidence interval would be given by (18.84;22.20)
Part c: Build a 95% confidence interval for the mean time in the system using all ten averages collected.
Data: 25.2, 19.7, 23.6, 18.6, 21.4, 22.1, 26.0, 20.2, 16.4, and 17.9
The mean calculated for this case is [tex]\bar X=21.11[/tex]
The sample deviation calculated [tex]s=3.154[/tex]
In order to calculate the critical value [tex]t_{\alpha/2}[/tex] we need to find first the degrees of freedom, given by:
[tex]df=n-1=10-1=9[/tex]
Since the Confidence is 0.95 or 95%, the value of [tex]\alpha=0.05[/tex] and [tex]\alpha/2 =0.025[/tex], and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,9)".And we see that [tex]t_{\alpha/2}=2.262[/tex]
Now we have everything in order to replace into formula (1):
[tex]21.11-2.262\frac{3.154}{\sqrt{10}}=18.85[/tex]
[tex]21.11+2.262\frac{3.154}{\sqrt{10}}=23.37[/tex]
So on this case the 95% confidence interval would be given by (18.85;23.37)
And as we can see the confidence intervals are very similar for the 3 cases.
Steel rods are manufactured with a mean length of 29 centimeter(cm). Because of variability in the manufacturing process, the lengths of the rods are approximately normally distributed with a standard deviation of 0.07 cm. Complete parts (a) to (d)
(a) What proportion of rods has a length less than 28.9 cm?
(b) Any rods that are shorter than 28.84 cm or longer than 29.16 cm are discarded. What proportion of rods will be discarded?
(c) Using the results of part (b) if 5000 rods are manufactured in a day, how many should the plant manager expect to discard?
(d) If an order comes in for 10,000 steel rods, how many rods should the plant manager expect to manufacture if the order states that all rods must be between
28.9 cm and 29.1 cm?
The problem involves computing z-scores and finding corresponding proportions in a normal distribution, then using these proportions to estimate rod discard rates and the amount of rods to manufacture. The mean and standard deviation of rod lengths provided are used for z-score calculations.
Explanation:In this problem, we are dealing with a normal distribution scenario where the mean (μ) is given as 29 cm and the standard deviation (σ) is 0.07 cm.
(a) Proportion of rods less than 28.9 cmTo find the proportion, we can firstly calculate the z-score using the formula z = (x - μ)/σ, where x is the required value (28.9 cm). The z-score helps us express how far our data point is from the mean in terms of standard deviations. Using standard normal distribution tables or a calculator, we can then determine the proportion of rods with lengths less than 28.9 cm.
(b) Proportion of rods to be discardedA similar strategy is used. Calculate the z-scores for 28.84 cm and 29.16 cm, then use these to find proportions. The proportion of discarded rods would be the sum of these two.
(c) Number of rods to be discardedUsing the proportion obtained in (b), multiply it by the total number of rods manufactured in a day (i.e., 5000) to get the expected number of rods to be discarded.
(d) Number of rods to be manufacturedIn this part, calculate the z-scores for 28.9 and 29.1 cm, then find the proportion of rods within these lengths using the tables or calculator. As this proportion represents the acceptable rods, divide the required amount of rods (i.e., 10,000) by this proportion to calculate the expected total rods to be manufactured to fulfill the order.
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To find the proportion of rods that have a length less than 28.9 cm, we use the standard normal distribution table. The proportion of rods that will be discarded is found by calculating the z-scores for the lower and upper bounds of the range. The expected number of discarded rods can be estimated by multiplying the proportion of discarded rods by the number of rods manufactured. The number of rods that should be manufactured within a specified range can be calculated using the proportion of rods that fall within that range.
Explanation:To solve this problem, we will use the standard normal distribution table to find the proportion of rods that have a length less than 28.9 cm. We will also use the standard normal distribution table to find the proportion of rods that will be discarded when their length is outside the range of 28.84 cm to 29.16 cm. Finally, we will use the proportion of discarded rods to estimate the number of rods that the plant manager should expect to discard when manufacturing 5000 rods in a day. For part (d), we will assume that the lengths of the rods are normally distributed and calculate the number of rods that fall within the range of 28.9 cm to 29.1 cm when manufacturing 10,000 rods.
(a) To find the proportion of rods with a length less than 28.9 cm, we need to find the z-score corresponding to 28.9 cm. The z-score formula is given by z = (x - mean) / standard deviation. Plugging in the values, we get z = (28.9 - 29) / 0.07 = -1.43. Using the standard normal distribution table, we find that the proportion of rods with a length less than 28.9 cm is 0.0764 or 7.64%.
(b) To find the proportion of rods that will be discarded, we need to find the z-scores corresponding to 28.84 cm and 29.16 cm. The z-score for 28.84 cm is z = (28.84 - 29) / 0.07 = -2.29 and the z-score for 29.16 cm is z = (29.16 - 29) / 0.07 = 2.29. Using the standard normal distribution table, we find that the proportion of rods with a length shorter than 28.84 cm or longer than 29.16 cm is 0.0485 or 4.85%. Therefore, the proportion of rods that will be discarded is 4.85%.
(c) To estimate the number of rods that the plant manager should expect to discard when manufacturing 5000 rods in a day, we multiply the proportion of discarded rods by the number of rods manufactured. The expected number of discarded rods is 0.0485 x 5000 = 242.5 or approximately 243 rods.
(d) To calculate the number of rods that the plant manager should expect to manufacture when the order states that all rods must be between 28.9 cm and 29.1 cm, we need to find the proportion of rods that fall within this range. The z-scores for 28.9 cm and 29.1 cm are calculated as z1 = (28.9 - 29) / 0.07 = -1.43 and z2 = (29.1 - 29) / 0.07 = 1.43. Using the standard normal distribution table, we find that the proportion of rods that fall within this range is 0.8471 or 84.71%. Therefore, the number of rods that the plant manager should expect to manufacture when the order states that all rods must be between 28.9 cm and 29.1 cm is 0.8471 x 10000 = 8471 rods.
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A researcher has a hypothesis that a specific drug may have a higher prevalence of side effects among members of the African American population than members of the Caucasian population. Which statistical technique might the researcher want to use when designing a study to test their hypothesis
A. Stratification
B. Crossover matching
C. Matching
D. Randomization
Answer:
A. Stratification
Step-by-step explanation:
Stratified random sampling is used when the researcher wants to highlight a specific subgroup within an entire population.
Stratification technique is mainly used to reduce the population differences and to increase the efficiency of the estimates. In this method the population is divided into a number of subgroups or strata.
Each strata should be so formed such that they are homogeneous as far as possible.
Final answer:
When examining the hypothesis about drug side effects in different populations, Randomization is the most appropriate statistical technique. It helps in reducing bias and ensures equal chances of group assignment, providing more reliable results in comparing the effects across populations.(Option D)
Explanation:
A researcher examining the hypothesis that a specific drug may exhibit a higher prevalence of side effects among the African American population compared to the Caucasian population could employ several statistical techniques to design the study. However, the most appropriate option provided is Randomization. Randomization helps in mitigating bias and ensures that each participant has an equal chance of being assigned to either the experimental or control group. This process decreases the likelihood of systematic differences between groups and allows any effects observed to be more confidently attributed to the drug under study rather than external factors.
Other options like Stratification, Crossover matching, and Matching could also play roles in different aspects of study design, but when testing a hypothesis about a drug's effects across different populations, randomization is crucial. It aligns with principles of experimental design that seek to control, to the extent possible, for variables that could influence the outcome, ensuring that the treatment group and control group are comparable at the beginning of the study.
The time to fly between New York City and Chicago is uniformly distributed with a minimum of 120 minutes and a maximum of 150 minutes.
What is the probability that a flight is between 125 and 140 minutes?
A. 1.00.
B. 0.50.
C. 0.33.
D. 0.12.
E. 0.15
Answer:
B. 0.50.
Step-by-step explanation:
An uniform probability is a case of probability in which each outcome is equally as likely.
For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.
The probability of a measure X being between two values c and d, in which d is larger than c, is given by the following formula:
[tex]P(c \leq X \leq d) = \frac{d - c}{b - a}[/tex]
Uniformly distributed with a minimum of 120 minutes and a maximum of 150 minutes.
This means that [tex]a = 120, b = 150[/tex]
What is the probability that a flight is between 125 and 140 minutes?
This is
[tex]P(125 \leq X \leq 140) = \frac{140 - 125}{150 - 120} = 0.5[/tex]
So the correct answer is:
B. 0.50.
Shaki makes and sells backpack danglies. The total cost in dollars for Shaki to make q danglies is given by c(q)= 75+2q+0.015q^2 . Find the quantity that minimizes Shaki
the quantity that minimizes Shaki's cost is [tex]\( \frac{200}{3} \)[/tex], or approximately [tex]\( 66.67 \)[/tex] danglies.
To find the quantity that minimizes Shaki's cost function [tex]\( c(q) = 75 + 2q + 0.015q^2 \)[/tex], we need to find the value of q where the derivative of [tex]\( c(q) \)[/tex] with respect to [tex]\( q \)[/tex] is zero.
Given the cost function:
[tex]\[ c(q) = 75 + 2q + 0.015q^2 \][/tex]
We'll find the derivative [tex]\( c'(q) \)[/tex] with respect to q and set it equal to zero to find the critical points.
[tex]\[ c'(q) = \frac{d}{dq} (75 + 2q + 0.015q^2) \][/tex]
[tex]\[ c'(q) = 2 + 0.03q \][/tex]
Now, we'll set [tex]\( c'(q) \)[/tex] equal to zero and solve for q:
[tex]\[ 2 + 0.03q = 0 \][/tex]
[tex]\[ 0.03q = -2 \][/tex]
[tex]\[ q = \frac{-2}{0.03} \][/tex]
[tex]\[ q = -\frac{200}{3} \][/tex]
Since the quantity q must be positive in this context, we disregard the negative solution. Therefore, the critical point occurs at [tex]\( q = \frac{200}{3} \)[/tex].
To determine whether this critical point corresponds to a minimum, we'll analyze the second derivative [tex]\( c''(q) \)[/tex]. If [tex]\( c''(q) > 0 \)[/tex] at [tex]\( q = \frac{200}{3} \)[/tex], then it's a local minimum.
[tex]\[ c''(q) = \frac{d^2}{dq^2} (2 + 0.03q) \][/tex]
[tex]\[ c''(q) = 0.03 \][/tex]
Since [tex]\( c''(q) \)[/tex] is positive, the critical point [tex]\( q = \frac{200}{3} \)[/tex] corresponds to a minimum.
Therefore, the quantity that minimizes Shaki's cost is [tex]\( \frac{200}{3} \)[/tex], or approximately [tex]\( 66.67 \)[/tex] danglies.
"Consider the following argument:
a. George and Mary are not both innocent.
b. If George is not lying, Mary must be innocent.
c. Therefore, if George is innocent, then he is lying.
Let ???? be the proposition "George is innocent", m be the proposition "Mary is innocent", and let ???? be the proposition "George is lying"."
1. Write a propositional formula F involving variables g, m, l such that the above argument is valid if and only if F is valid.
2. Is the above argument valid? If so, prove its validity by proving the validity of F. If not, give an interpretation under which F evaluates to false.
College Mathematics 10+5 pts
"Consider the following argument:
a. George and Mary are not both innocent.
b. If George is not lying, Mary must be innocent.
c. Therefore, if George is innocent, then he is lying.
Let ???? be the proposition "George is innocent", m be the proposition "Mary is innocent", and let ???? be the proposition "George is lying"."
1. Write a propositional formula F involving variables g, m, l such that the above argument is valid if and only if F is valid.
2. Is the above argument valid? If so, prove its validity by proving the validity of F. If not, give an interpretation under which F evaluates to false.
Answer
1. [tex]F = ((g\cap \sim m)\cup(\sim g\cap m)\cap(\sim l\to m))\to(g\to l) [/tex]
2. It is valid. See explanation for proof.
Step-by-step explanation
1. Statement a is an exclusive OR of [tex]g[/tex] and [tex]m[/tex]. This is because only one of them is innocent while the other is not. That is [tex]g[/tex] is true and [tex]m[/tex] is false or [tex]g[/tex] is false and [tex]m[/tex] is true.
Statement b is an implication that [tex]\sim l \to m[/tex].
Statement c is another implication that [tex]g\to l[/tex].
The presence of the word "therefore" in statement c means it is an implication from statement a AND statement b. So we have
[tex]F = ((g\cap \sim m)\cup(\sim g\cap m)\cap(\sim l\to m))\to(g\to l) [/tex]
2.
The validity will be proved using a truth table. [tex]F[/tex] is valid if the last column contains only true values i.e. truth values of T.
From the table (in the attached image), [tex]c[/tex] represents the statement a, [tex]d[/tex] represents statement b and [tex]f[/tex] represents statement c. The last column, which represents [tex]F[/tex], is valid as all its entries are T.
To translate the argument into logic notation, one could write it as ((¬g ∨ m) ∧ (¬l → m)) → ((g → ¬l). Upon considering the case where both George and Mary are innocent, and George is not lying, it can be observed that the argument is invalid.
Explanation:1. The propositional formula F can be written as: ((¬g ∨ m) ∧ (¬l → m)) → ((g → ¬l). This translates the given argument into logical notation.
2. This argument is not valid. An easy way to prove this is by considering a scenario where both George and Mary are innocent, hence g and m are both true, and let l be the proposition 'George is lying', so l is false. In this case, the left-hand side of your main implication results true ((¬g ∨ m) ∧ (¬l → m)) = (false ∨ true) ∧ (true → true) = true ∧ true = true), but the right-hand side of your main implication results false (g → ¬l = true → false = false) hence the full implication results false, which makes the argument invalid.
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(10 pts) A device has a sensor connected to an alarm system. The sensor triggers 95% of the time if dangerous conditions exist and 0.5% of the time if conditions are normal. Dangerous conditions exist 0.5% of the time in general. (a) What is the probability of a false alarm
Answer:
The probability of a false alarm is 0.5116 .
Step-by-step explanation:
Let us indicate three events :
Event A = Alarm system triggers
Event B = Dangerous conditions exist
Event B' = Normal conditions exist
Now we are given with P(A/B) which means probability of alarm getting triggered given the dangerous conditions exist , P(A/B') which means probability of alarm getting triggered given the normal conditions exist and P(B) which means the probability of dangerous conditions existing i.e.
P(A/B) = 0.95 P(A/B') = 0.005 P(B) = 0.005 P(B') = 1 - P(B) = 0.995
(a) The probability of a false alarm means given the alarm gets triggered probability that there was normal conditions i.e. P(B'/A)
P(B'/A) = [tex]\frac{P(A\bigcap B')}{P(A)}[/tex]
Now P(A) = P(B) * P(A/B) + P(B') * P(A/B') {This representing Probability of alarm getting triggered in both the conditions]
P(A) = 0.005 * 0.95 + 0.995 * 0.005 = 9.725 x [tex]10^{-3}[/tex]
Since P(A/B') = 0.005
[tex]\frac{P(A\bigcap B')}{P(B')}[/tex] = 0.005 So, [tex]P(A\bigcap B')[/tex] = 0.005 * 0.995 = 4.975 x [tex]10^{-3}[/tex]
Therefore, P(B'/A) = [tex]\frac{P(A\bigcap B')}{P(A)}[/tex] = [tex]\frac{4.975*10^{-3} }{9.725*10^{-3} }[/tex] = 0.5116 .
Find the volume of the pyramid. Round your answer to the nearest tenth.
8.6 mm
15.5 mm
12.5 mm
The volume of the pyramid is
mm?.
Answer:
from my opinion second option is right
The sample space of a random experiment is {a,b,c,d,e} with probabilities 0.1,0.1,0.2,0.4, and 0.2, respectively. Let A denote the event {a,b,c}, and let B denote the even t {c,d,e}. Determine the following:
a. P(A)
b. P(B)
c. P(A’)
d. P(AUB)
e. P(AnB)
Answer with Step-by-step explanation:
We are given that a sample space
S={a,b,c,d,e}
P(a)=0.1
P(b)=0.1
P(c)=0.2
P(d)=0.4
P(e)=0.2
a.A={a,b,c}
P(A)=P(a)+P(b)+P(c)
P(A)=0.1+0.1+0.2=0.4
b.B={c,d,e}
P(B)=P(c)+P(d)+P(e)=0.2+0.4+0.2=0.8
c.A'=Sample space-A={a,b,c,d,e}-{a,b,c}={d,e}
P(A')=P(d)+P(e)=0.4+0.2=0.6
d.[tex]A\cup B[/tex]={a,b,c,d,e}
[tex]P(A\cup B)[/tex]=P(a)+P(b)+P(c)+P(d)+P(e)=0.1+0.1+0.2+0.4+0.2=1
e.[tex]A\cap B[/tex]={c}
[tex]P(A\cap B)=P(c)=0.2[/tex]
Five cards are drawn from an ordinary deck of 52 playing cards. What is the probability that the hand drawn is a full house? (A full house is a hand that consists of two of one kind and three of another kind.)
Answer:
The required probability is 0.00144 or 0.144%.
Step-by-step explanation:
Consider the provided information.
Five cards are drawn from an ordinary deck of 52 playing cards.
A full house is a hand that consists of two of one kind and three of another kind.
The total number of ways to draw 5 cards are: [tex]^{52}C_5=\frac{52!}{5!47!}[/tex]
Now we want two of one kind and three of another.
Let the hand has the pattern AAABB, where A and B are from distinct kinds. The number of such hands are:
[tex]^{13}C_1\times^{4}C_3\times^{12}C_1\times^{4}C_2=\frac{13!}{12!}\times\frac{4!}{3!}\times\frac{12!}{11!}\times\frac{4!}{2!2!}[/tex]
Thus, the required probability is:
[tex]\frac{^{13}C_1\times^{4}C_3\times^{12}C_1\times^{4}C_2}{^{52}C_5}=\frac{\frac{13!}{12!}\times\frac{4!}{3!}\times\frac{12!}{11!}\times\frac{4!}{2!2!}}{\frac{52!}{5!47!}}[/tex]
[tex]=\frac{3744}{2598960}\\\\\approx0.00144[/tex]
Hence, the required probability is 0.00144 or 0.144%.
The sum of the diameters of the largest and smallest pizzas sold at a pizza shop is 25 inches. The difference in their diameters is 15 inches. Find the diameters of the largest and smallest pizzas.
Answer:
20 inches and 5 inches
Step-by-step explanation:
Let the diameter of the largest and the smallest pizza be Y and X respectively.
Then,
Y+X = 25 ........................... Equation 1
Y-X = 15 ............................ Equation 2
Solve equation 1 and equation 2 simultaneously.
Add equation 1 and equation 2
Y+Y = +X+(-X)+25+15
2Y = 40
Y = 40/2
Y = 20 inches.
Also,
Substitute the value of Y into equation 1
20+X=25
X = 25-20
X = 5 inches.
Hence the diameter of the largest and the smallest pizzas = 20 inches and 5 inches
Final answer:
The smallest pizza has a diameter of 5 inches, and the largest pizza has a diameter of 20 inches.
Explanation:
The diameters of the largest and smallest pizzas are 20 inches and 5 inches, respectively.
To find the diameters of the pizzas:
Let x be the diameter of the smallest pizza and y be the diameter of the largest pizza.
We have the system of equations x + y = 25 and y - x = 15.
Solving these equations simultaneously, we get y = 20 and x = 5.
Which, if any, of A. (4, π/6), B. (−4, 7π/6), C. (4, 13π/6), are polar coordinates for the point given in Cartesian coordinates by P(2, 2 √ 3)?
Final answer:
Explaining the polar coordinates for given Cartesian coordinates.
Explanation:
Polar Coordinates of Points:
Point A(2, 2√3): Polar coordinates are (4, π/6).
Point B(-4, 7π/6): Wrong polar coordinates as it should be (4, 11π/6).
Point C(4, 13π/6): Wrong polar coordinates.
According to CNN business partner Careerbuilder, the average starting salary for accounting graduates in 2018 was at least $57,413. Suppose that the American Society for Certified Public Accountants planned to test this claim by randomly sampling 200 accountants who graduated in 2018. State the appropriate null and alternative hypotheses.
Answer:
Null hypothesis: The American Society for Certified Public Accountants says the average starting salary of accountants who graduated in 2018 is $57,413
Alternate hypothesis: The American Society for Certified Public Accountants says the average starting salary of accountants who graduated in 2018 is less than or equal to $57,413
Step-by-step explanation:
A null hypothesis is a statement from a population parameter that is subject to testing. It is expressed with equality.
An alternate hypothesis is also a statement from the population parameter that negates the null hypothesis. It is expressed with inequality
Suppose that a company’s sales were $5,000,000 three years ago. Since that time sales have grown at annual rates of 10
percent,–10 percent, and 25 percent.
a Find the geometric mean growth rate of sales over this three-year period.
b Find the ending value of sales after this three-year period.
Answer:
≈ 0.07
Step-by-step explanation:
To find the geometric mean over this three-year period, we plug in the values for the yearly return rates into the equation for the geometric mean.
The geometric mean growth rate of sales over this three-year period is 7.36%. Also, the ending value of sales after this three-year period is $6,187,500.
Geometric Mean (GM) is the average value or mean which signifies the central tendency of the set of numbers by finding the product of their values. Basically, we multiply the numbers altogether and take the nth root of the multiplied numbers, where n is the total number of data values.
[tex](1+G)^3 = (1+0.1)(1-0.1)(1+0.25)\\\\(1+G)^3 = 1.2375\\\\(1+G) = \sqrt[3]{1.2375} = 1.0736\\\\G = 0.0736[/tex]
G = 7.36 %
Also,
sales in year 0 = $5,000,000
annual Growth rate of year 1 = 10%
Sales in year 1 : $5,000,000 + 10% of $5,000,000 = [tex]5,000,000 + \frac{10}{100} *$5,000,000 = $5,500,000[/tex]
annual Growth rate of year 2 = -10%
Sales in year 2 : $5,500,000 - 10% of $5,500,000 = [tex]5,500,000 - \frac{10}{100} *$5,500,000 = $4,950,000[/tex]
annual Growth rate of year 3 = 25%
Sales in year 3 : $4,950,000 + 25% of $4,950,000 = [tex]4,950,000 + \frac{25}{100} *4,950,000 = $6,187,500[/tex]
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The days maturity for a sample of 5 money market funds areshown here. The dollar amounts invested in the funds areprovided. Use the weighted mean to determine the mean numberof days to maturity for dollars invested in these 5 money marketfunds.COL1 Days tomaturity 20 12 7 5 6COL2 $$ Value (millions) 20 30 10 15 10
Final answer:
The weighted mean number of days to maturity for dollars invested in the 5 money market funds is approximately 11.35 days. This is calculated by taking the product of the days to maturity and the corresponding money value for each fund, summing these products, and then dividing by the total money value invested.
Explanation:
The question asks to calculate the weighted mean of days to maturity for dollars invested in several money market funds with varying maturities and dollar values. To compute this, we multiply each fund's days to maturity by its dollar value (in millions), sum these products, and then divide by the total of the dollar values. Here's the calculation:
(20 days * $20 million) + (12 days * $30 million) + (7 days * $10 million) + (5 days * $15 million) + (6 days * $10 million) = $400 million-days + $360 million-days + $70 million-days + $75 million-days + $60 million-days
Total million-days = $965 million-days
Total value of all funds = $85 million
Weighted mean days to maturity = Total million-days / Total value of all funds = $965 million-days / $85 million = 11.35 days
So, the weighted mean number of days to maturity for the dollars invested in these 5 money market funds is approximately 11.35 days.
kevin durant of the oklahoma city thunder & kobe bryant of the los angeles lakers were the leading scorers in the NBA for the 2012-2013 regular season. Together they scored 4413 points, with bryant scoring 147 fewer points than durant. how many pointsdid each of them score?
Answer:
Bryant: 2059.5 (RIP)
Durant:2353.5
Step-by-step explanation:
To find how many points Kevin Durant and Kobe Bryant scored, set up equations based on the given information. Kevin Durant scored 2280 points and Kobe Bryant scored 2133 points during the 2012-2013 NBA regular season.
Explanation:The question asks us to determine how many points Kevin Durant and Kobe Bryant scored individually during the 2012-2013 NBA regular season given that together they scored 4413 points and Kobe Bryant scored 147 fewer points than Kevin Durant.
To solve this, we can set up two equations based on the information provided:
We can substitute the second equation into the first to find Durant's score:
Now that we have Durant's score, we can use it to find Bryant's score:
Therefore, Kevin Durant scored 2280 points and Kobe Bryant scored 2133 points during the 2012-2013 NBA regular season.
1. Rewrite each condition below in valid Java syntax (give a boolean expression): a. x > y > z b. x and y are both less than 0 c. neither x nor y is less than 0 d. x is equal to y but not equal to z
Answer:
Here are Boolean expressions in Java syntax.
Step-by-step explanation:
For each part:
a) (x > y && y > z)
b) x == y && x < 0, or x < 0 && y < 0, or x == y && y < 0 (which is essentially the first example)
c) (x == y && x >= 0), or (x >= 0 && y >= 0), or (x == y && y >= 0) (for the first and third, once the first condition establishes that x is equal to y, if either x or y is greater than or equal to 0, then they are both not less than 0)
d) (x == y && x != z), or (x == y && y != z)
Investments Suppose that you have $4000 to invest and you invest x dollars at 10% and the remainder at 896, write expressions in x that represent (a) the amount invested at 8%, (b) the interest earned on the x dollars at 10%, (c) the interest earned on the money invested at 8% (d) the total interest earned.
Answer:
Step-by-step explanation:
you have $4000 to invest and you invest x dollars at 10% and the remainder at 8℅.
a) an expression in x that represent the amount invested at 8% is
4000 - x
b) The The formula for simple interest is expressed as
I = PRT/100
Where
P represents the principal
R represents interest rate
T represents time in years
I = interest after t years
From the information given
P = $x
R = 10%
Assuming the investment is for 1 year, then interest,
I = (x × 10 × 1)/100
I = $0.1x
c) P = 4000 - x
R = 8℅
I = [(4000 - x) × 8 × 1)]/100
I = (32000 - 8x)/100
I = 320 - 0.08x
d) the total interest earned is
I = 0.1x + 320 - 0.08x
I = 0.02x + 320
Disks of polycarbonate plastic from a supplier are analyzed for scratch and shock resistance. The results from 100 disks are summarized as follows: Shock resistance High LowScratch High 70 9Resistance Low 16 5Let A denote the event that a disk has high shock resistance, and let B denote the event that a disk has high scratch resistance. Are events A and B independent?
Answer:
Part a
The probability that the event disk has high shock resistance is 0.86
Part b
The probability that a disk has high scratch resistance given that the disk has high shock resistance is 0.8140
Step-by-step explanation:
(a).
From the given information,
Let A denote the event that a disk has high shock resistance,
and let B denote the event that a disk has high scratch resistance.
SHOCK HIGH(A) SHOCK LOW(A) TOTAL
SCRATCH
HIGH(B) 70 9 79
RESISTANCE 16 5 21
LOW(B)
TOTAL 86 14 100
Compute P(A).
Therefore, the probability value of the event A is 0.86.
Part a
The probability that the event disk has high shock resistance is 0.86
Explanation | Hint for next step
Based on the given information, the probability that the event disk has high shock resistance is 0.86. That means it is approximately equal to 86%.
Step 2 of 2
(b)
From the given information,
Let A denote the event that a disk has high shock resistance,
and let B denote the event that a disk has high scratch resistance.
SHOCK HIGH(A) SHOCK LOW(A) TOTAL
SCRATCH
HIGH(B) 70 9 79
SCRATCH
LOW(B) 16 5 21
TOTAL 86 15 100
ComputeP(B/A) = P(A∩B) /P(A) ;P(A) > 0
P(A∩B) =70/100
=0.70
From the part [a], the probability value of the event A is P(A) =0.86 .
Therefore,
P( {B/A} = P(A∩B) /P(A)
= 0.70 /0.86
=0.8140
Part b
The probability that a disk has high scratch resistance given that the disk has high shock resistance is 0.8140
Explanation | Common mistakes
The disk with high scratch resistance is found to be 81.40% with the condition that the disk with high shock resistance is maintained.
Final answer:
Events A (high shock resistance) and B (high scratch resistance) in the context of polycarbonate plastic disks are not independent, as the calculated probabilities P(A ∩ B) and P(A)P(B) do not match.
Explanation:
Whether two events are independent can be determined by checking if the probability of one event occurring does not affect the probability of the other event. Mathematically, two events A and B are independent if and only if-
P(A ∩ B) = P(A)P(B)
Let's calculate this using the data provided from the analysis of 100 disks of polycarbonate plastic.
Total number of disks (n) = 100
Number of disks with high shock resistance (A) = 70 + 9 = 79
Number of disks with high scratch resistance (B) = 70 + 16 = 86
Number of disks with both high shock and scratch resistance (A ∩ B) = 70
The probability of A (P(A)) is thus 79/100, the probability of B (P(B)) is 86/100, and the probability of both A and B occurring (P(A ∩ B)) is 70/100. Now we multiply P(A) and P(B):
P(A)P(B) = (79/100) × (86/100) = 0.6794
However, P(A ∩ B) as observed is-
70/100 = 0.7
Since P(A ∩ B) does not equal P(A)P(B), the events A and B are not independent.
An air traffic controller has noted that it clears an average of seven planes per hour for landing. What is the probability that during the next two hours exactly 15 planes will be cleared for landing?a. 0.0989 b. Not enough information is given to answer the problem. c. 0.0033 d. 0.0651
Answer:
a) 0.0989, Option a
Step-by-step explanation:
The concept of Poisson probability distribution is used as shown in the attached file.
Describe a normal probability distribution. a. bell-shaped.b. mean, median, and mode all equivalent.c. bimodal.d. symmetric around the mean.e. skewed to the right.f. models discrete random variables.g. most of the data fall within 3 standard deviations from the mean. h. uniform-shaped.
Answer:
a) bell-shaped.
b) mean, median, and mode all equivalent.
d) symmetric around the mean.
g) most of the data fall within 3 standard deviations from the mean.
Step-by-step explanation:
We have to describe a normal distribution.
a. bell-shaped.
This is true a normal distribution is a bell shaped distribution.
b. mean, median, and mode all equivalent.
This is true for a normal distribution.
Mean = Mode = Median
c. Bimodal
The is not true about the normal distribution. A normal distribution is unimodal and the mode is equal to the mean of the distribution.
d. symmetric around the mean.
This is true. The normal distribution is centered around the mean
e. skewed to the right.
This is not a property of normal distribution.
f. models discrete random variables.
Normal distribution is a continuous distribution.
g. most of the data fall within 3 standard deviations from the mean.
This is true. According to Empirical rule, almost all the data lies within three standard deviation of mean.
h. uniform-shaped
This is not true. A normal distribution is bell shaped.
The options that properly describe a normal distribution are;
A) Bell Shaped
B) Mean, median and mode are equivalent
D) Symmetric about the mean
G) most of the data fall within 3 standard deviations from the mean
Some of the properties of normal distribution are that;
The mean, mode and median are all equal.The curve is symmetric at the center around the mean. This implies a bell shaped curve. Exactly half of the values are to the left of center and exactly half the values are to the right.The total area under the curve is 1 It's a continuous distributionLet us look at the options;
A) this is correct from the properties listed above. B) This is also correct from the properties listed above. C) This is not true because the mode is equal to the median and the mean and thus can only be unimodal. D) This is true from the properties listed above. E) From property 3, this is wrong as it is not skewed to the right since it has half values to the left and half to the right. F) This is not true because normal distribution is continuous and not discrete. G) This is true based on the empirical rule of normal distribution because Empirical Rule states that 99.7% of data observed following a normal distribution lies within 3 standard deviations of the mean. H) Not true as from property 2 we can see that it is bell shaped.Read more about normal distribution at;https://brainly.com/question/4514629
A forensic psychologist studying the accuracy of a new type of polygraph (lie detector) test instructed a participant ahead of time to lie about some of the questions asked by the polygraph operator. On average, the current polygraph test is 75% accurate, with a standard deviation of 6.5%. With the new machine, the operator correctly identified 83.5% of the false responses for one participant. Using the.05 level of significance, is the accuracy of the new polygraph different from the current one? Fill in the following information: Assuming an ?-0.05, determine the z-score cutoff for the rejection region. Calculate the test statistic for the given data Zobt Based on the data above, finish the statement about your decision: Based on the observed z-score, we would decide to (accept, reject, fail to reject, fail to accept) hypothesis. the (null, alternative)
Answer:
[tex]z=\frac{83.5-75}{6.5}=1.31[/tex]
The rejection zone for this case would be:
[tex] z> 1.96 \cup Z<-1.96[/tex]
[tex]p_v =2*P(z>1.31)=0.1901[/tex]
If we compare the p value and the significance level given [tex]\alpha=0.05[/tex] we see that [tex]p_v>\alpha[/tex] so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the true mean is significantly different from 75 at 5% of significance.
Step-by-step explanation:
Data given and notation
[tex]\bar X=83.5[/tex] represent the sample mean
[tex]\sigma=6.5[/tex] represent the population standard deviation for the sample
[tex]\mu_o =75[/tex] represent the value that we want to test
[tex]\alpha=0.05[/tex] represent the significance level for the hypothesis test.
t would represent the statistic (variable of interest)
[tex]p_v[/tex] represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to conduct a hypothesis in order to check if the mean is different from 75, the system of hypothesis would be:
Null hypothesis:[tex]\mu = 75[/tex]
Alternative hypothesis:[tex]\mu \neq 75[/tex]
For this case we know the population deviation so is better apply a z test to compare the actual mean to the reference value, and the statistic is given by:
[tex]z=\frac{\bar X-\mu_o}{\sigma}[/tex] (1)
z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
[tex]z=\frac{83.5-75}{6.5}=1.31[/tex]
Cutoff for the rejection regon
Since our significance level is [tex] \alpha=0.05[/tex] and we are conducting a bilateral test we need to find a quantile in the standard normal distribution that accumulates 0.025 of the area on each tail.
And for this case those values are [tex] z_{crit}= \pm 1.96[/tex]
So the rejection zone for this case would be:
[tex] z> 1.96 \cup Z<-1.96[/tex]
Our calculated value is not on the rejection zone. So we fail to reject the null hypothesis.
P-value
Since is a two sided test the p value would be given by:
[tex]p_v =2*P(z>1.31)=0.1901[/tex]
Conclusion
If we compare the p value and the significance level given [tex]\alpha=0.05[/tex] we see that [tex]p_v>\alpha[/tex] so we can conclude that we have enough evidence to fail reject the null hypothesis, so we can't conclude that the true mean is significantly different from 75 at 5% of significance.
Final answer:
To determine if the new polygraph test's accuracy significantly differs from the current one, we compare the calculated test statistic with the critical z-score of ±1.96 at an alpha level of 0.05. The process involves hypothesis testing, where rejecting or failing to reject the null hypothesis depends on whether the test statistic exceeds the critical value.
Explanation:
The question is about determining if the accuracy of a new type of polygraph test is statistically different from the current one using hypothesis testing. Given an alpha level (α) of 0.05 (5% level of significance), the critical z-score for a two-tailed test is ±1.96. This critical value defines the cutoff points for the rejection regions. To calculate the test statistic (Zobt), we use the formula:
Zobt = (X - μ) / (σ / √n),
where X is the sample mean (83.5%), μ is the population mean (75%), σ is the standard deviation (6.5%), and √n is the square root of the sample size. Given that only one participant's data is used, √n is 1 for this scenario, which simplifies our formula. Unfortunately, without the exact sample size for a more precise calculation or this being a theoretical scenario with one participant, we remark on the process rather than providing a numerical value for Zobt.
Based on the calculated Zobt, if it exceeds the critical z-score (1.96 or -1.96), we reject the null hypothesis indicating that there is a statistically significant difference between the new polygraph's accuracy and the current one. If Zobt does not exceed the critical value, we fail to reject the null hypothesis, indicating no significant difference.
Suppose you draw a card from a well shuffled deck of 52 what is the probability of drawing a 10 or jack
The probability of drawing a 10 or Jack will be 8/52.
What is probability?The chances of an event occurring are defined by probability. Probability has several uses in games, and in business to create probability-based forecasts.
The number of jack cards and 10 number cards from the pack of cards is 4,
The probability of drawing a 10 or jack is,
P = P(10) + P(J)
P = (4/52)+(4/52)
P= 8/52
Hence, the probability of drawing a 10 or Jack will be 8/52.
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Bottled water and medical supplies are to be shipped to victims of a hurricane by plane. Each plane can carry 90,000 pounds and a total volume of 6000 cubic feet. The bottled water weighs 20 pounds per container and measures 1 cubic foot. The medical kits each weigh 10 pounds and measure 2 cubic feet.
(a) How many containers of bottled water and how many medical kits can be sent on each plane?
Answer:4000 bottle containers and 1000
Medical kits
Step-by-step explanation:
The total weights the plane can take per trip is 90000lb. It implies that if we multiply the weight of each bottle container by the number of bottle container and add it to the product of the number medical kit and the weight of each medical kit, we will obtain a total weight of 90000lb.
If x is the number of bottle and y is the number of medical kit
20×x+10×y=90000....i
Also
The total volume the plane can take per trip is 6000ft³ It implies that if we multiply the volume of each bottle container by the number of bottle container and add it to the product of the number medical kit and the volume of each medical kit, we will obtain a total volume of 6000ft³.
Recall, x is the number of bottle and y is the number of medical kit
1×x+2×y=6000....ii
Combining equation i and ii and solving simultaneously,
x=4000 units and y= 1000 units in each plane trip
Answer:
Bottled water = 4000.
Medical kits = 1000.
Step-by-step explanation:
Let x = bottled water
y = medical kits
For the mass (in pounds):
20x + 10y = 90000
For the cubic ft:
x + 2y = 6000
Solving equation i and ii simultaneously,
x = 4000.
y = 1000.
Bottled water = 4000.
Medical kits = 1000.