A swimming school claimed that the average seven-year-old would be able to swim across an Olympic-sized pool in less than 120 seconds after taking lessons from their instructors. To test this claim, a consumer psychologist arranged for eight randomly selected seven-year-old children to take lessons at the school and recorded how long it took each child to swim across a pool at the end of the lessons.

The times (in seconds) were 60, 120, 110, 80, 70, 90, 100, and 130.

What conclusion would the psychologist draw following a t test for a single sample using 120 seconds as the "known" population mean and the .05 significance level? 13 points) across an

a. Sample mean:
b. Sample sum of squares:
c. Degrees of freedom:
d. The estimated population variance:

Answers

Answer 1

Answer:

Step-by-step explanation:

The mean of the set of data given is

Mean = (60 + 120 + 110 + 80 + 70 + 90 + 100 + 130)/8 = 95

Standard deviation = √(summation(x - mean)/n

n = 8

Summation(x - mean) = (60 - 95)^2 + (120 - 95)^2 + (110 - 95)^2 + (80 - 95)^2 + (70 - 95)^2 + (90 - 95)^2 + (100 - 95)^2 + (130 - 95)^2 = 4200

Standard deviation = √(4200/8) = 22.91

We would set up the hypothesis test. This is a test of a single population mean since we are dealing with mean

For the null hypothesis,

µ ≤ 120

For the alternative hypothesis,

µ > 120

This is a right tailed test.

Since the number of samples is small and no population standard deviation is given, the distribution is a student's t.

Since n = 8,

Degrees of freedom, df = n - 1 = 8 - 1 = 7

t = (x - µ)/(s/√n)

Where

x = sample mean = 95

µ = population mean = 120

s = samples standard deviation = 22.91

t = (95 - 120)/(22.91/√8) = - 3.09

We would determine the p value using the t test calculator. It becomes

p = 0.009

Since alpha, 0.05 > than the p value, 0.009, then we would reject the null hypothesis. Therefore, At a 5% level of significance, the sample data showed significant evidence that the average seven-year-old would be able to swim across an Olympic-sized pool in more than 120 seconds after taking lessons from their instructors.

Answer 2

Using the one - sample t test, we can conclude that average 7year old will swim in less than 120 hours

Given the data :

60, 120, 110, 80, 70, 90, 100, and 130. Sample size, n = 8

Using calculator :

Mean = ΣX/n = 760/8 = 95

Standard deviation = 24.49

The degree of freedom :

df = n - 1 df = 8 - 1 = 7

The hypothesis :

[tex]H_{0} : μ > 120 [/tex]

[tex]H_{1} : μ ≤ 120 [/tex]

From the equality sign in the alternative hypothesis, we have a left-tailed test

Test statistic :

[tex] \frac{x - μ}{\frac{s}{\sqrt{n}}} [/tex]

Inputting the values :

[tex] \frac{95 - 120}{\frac{24.49}{\sqrt{8}}} [/tex]

[tex] \frac{-25}{8.658} = - 2.887 [/tex]

Calculating the P-value :

α = 0.05 ; df = 7 ;

Pvalue = 0.012

Decison Region :

Reject Null if Pvalue is < α

Since 0.012 < 0.05 ; we reject [tex]H_{0} [/tex] and conclude that average 7year old will swim in less than 120 hours.

Learn more : https://brainly.com/question/16314496


Related Questions

To find the surface area of the figure shown, Mia found the surface area of the two triangular prisms and the rectangular prism. From this, Mia subtracted 6 ft2. Did Mia make an error?
Mia should have subtracted 16 square feet.
Mia needs to subtract another 6 square feet.
Mia must calculate each triangle separately.
There is no error—Mia is correct.

Answers

Answer:

Mia needs to subtract another 6 square feet

Step-by-step explanation:

Guessed it and got it right

Answer:

needs to subtract another 6 ft

Step-by-step explanation:

A six sided number cube has
one number, from 1 through 6,
on each cube. Determine the
probability of the following:
Pleven #)
7.SP.5

Answers

Answer:

Probability of even = 0.5

Step-by-step explanation:

Probability of even = total number of even numbers/ total number

Total number of Eve number = [ 2,4,6] = 3

Total numbers = [ 1,2,3,4,5,6] = 6

Probability of even = 3/6

Probability of even = 1/2

Probability of even = 0.5


Bridget has swimming lessons every fifth day and diving lessons every third day. If she had a swimming lesson and a diving lesson on May 5, when will be the next date on which she has both swimming and diving lessons?

Answers

Answer:

The 20th of May

Step-by-step explanation:

I made a chart like a calendar and started on the 5th of may and counted every 5 days for the swimming lessons and every 3 days. Then I saw when she had both swimming and driving lessons and the first time after the 5th is the 20th.

Answer:

Bridget will have both swimming and diving lessons on the 15th.

A major retail clothing store is interested in estimating the difference in mean monthly purchases by customers who use the​ store's in-house credit card versus using a​ Visa, Mastercard, or one of the other major credit cards. To do​ this, it has randomly selected a sample of customers who have made one or more purchases with each of the types of credit cards. The following represents the results of the sampling. ​In-House Credit Card National Credit Card Sample​ Size: 86 113 Mean Monthly​ Purchases: ​$45.67 ​$39.87 Standard​ Deviation: ​$10.90 ​$12.47 Suppose that the managers wished to test whether there is a statistical difference in the mean monthly purchases by customers using the two types of credit​ cards, using a significance level of​ 0.05, what is the value of the test statistic assuming the standard deviations are​ known? Round to two decimal places.

Answers

I don’t know but make sure to re-read and get the result equal to 100

A gardener is planting two types of trees: Type A is 8 feet tall and grows at a rate of 7 inches per year. Type B is 2 feet tall and grows at a rate of 13 inches per year. Algebraically determine exactly how many years it will take for these trees to be the same height.

Answers

Answer:

1 year

Step-by-step explanation:

8 + 7x = 2 + 13x

Move the 2 to the other side by subtracting 2 from both sides.

6 + 7x = 13x

Move the 7x to the other side by subtracting both sides by 7x.

6 = 6x

Divide both sides by 6.

1 = x

Therefore, x equals 1 and it will take 1 year for both trees to reach the same height.

4. The null hypothesis for the chi-square goodness-of-fit test states that the distribution of A. cases for each group is equal to the expected distribution based on theory/knowledge of the population. B. sample means is equal to expectation based on the expected frequency. C. sample means for each group is equal. D. the sample means is equal to the expected distribution based on theory/knowledge of the population.

Answers

Answer:

D. the sample means is equal to the expected distribution based on theory/knowledge of the population.

Step-by-step explanation:

The Chi square goodness-of-fit test is used in statistical analysis to determine if the observed value in a collection of data, is significantly different from the expected value. Theoretical distribution which could be classified as normal, binomial, or poisson, are compared against the empirical distribution.To run a chi square goodness-of-fit test, we first formulate the null and alternate hypothesis. The degrees of freedom are then observed from the data given and the hypothesis is tested.

The null hypothesis assumes that the observed frequencies are equal to the expected frequencies. If there is a considerable difference, then the null hypothesis is rejected.

How many solutions does the equation 3(x + 2) – 10 = 4x – 6 + x have?

Answers

Answer:

1

Step-by-step explanation:

3(x+2)-10=4x-6+x

3x+6-10=5x-6

2x=2

x=1

This is the only solution to this equation, meaning that there is only one solution to the equation. Hope this helps!

The equation 3(x + 2) - 10 = 4x - 6 + x has one solution, which is x = 1. After simplifying the equation and solving for x, we confirm that substituting x = 1 back into the equation results in an identity, indicating that this is the correct solution.

To determine how many solutions the equation 3(x + 2) \\- 10 = 4x \\- 6 + x has, we must first simplify the equation and solve for x.

Let's simplify both sides of the equation:

Distribute the 3 on the left side: 3x + 6 \\- 10 = 4x \\- 6 + x.

Combine like terms on the right side: 3x \\- 4 = 5x \\- 6.

Get all the x terms on one side and constants on the other: 3x \\- 5x = \\-6 + 4.

Simplify the equation: \ -2x = \\-2.

Divide both sides by \\-2 to solve for x: x = 1.

So, the solution to the equation is x = 1. To verify that this is the solution, we can substitute x = 1 back into the original equation and check that it holds true, which would confirm that the equation is an identity. In this case, the substitution leads to an identity, confirming that x = 1 is the correct and only solution to the equation.

Lauren plans to deposit $6000 into a bank account at the beginning of next month and $225/month into the same account at the end of that month and at the end of each subsequent month for the next 4 years. If her bank pays interest at a rate of 3%/year compounded monthly, how much will Lauren have in her account at the end of 4 years?

Answers

Answer:

$18206.5

Step-by-step explanation:

Considering,  r = interest rate

    n = number of intervals

    t = duration of the payment

    A = monthly installment  

   PV = Present Value

   FV = Final Value

Using the formula

FV=PV (1+ r/n[tex])^{nt-1[/tex] + a((1+ r/n[tex])^{nt[/tex]-1/[tex]\frac{r}{n}[/tex])

FV=6000[tex](1+ \frac{0.03}{12} )^{(12)(4)-1} +225\frac{(1+0.03/12)^{(12)(4)}-1 )}{0.03/12}[/tex]

FV= 6747 + 11459.5

FV=18206.5

Her balance in 4 years is $18206.5

Sherry is cooking chicken for her family. She wants to be sure the chicken has an internal temperature of at least 170 degrees Fahrenheit. She uses a thermometer to measure the internal temperature at four randomly chosen places. The minimum reading in the sample is 180 degrees Fahrenheit. Identify the population, the parameter, the sample, and the statistic. Population, minimum temperature of 170 degrees Fahrenheit; parameter, all chicken meat temperature readings; sample, four random thermometer readings; statistic, minimum sample reading of 180 degrees Fahrenheit Population, all chicken meat temperature readings parameter, minimum temperature of 170 degrees Fahrenheit; sample, minimum sample reading of 180 degrees Fahrenheit; statistic, four random thermometer readings Population, four random thermometer readings; parameter, all chicken meat temperature readings; sample, minimum temperature of 170 degrees Fahrenheit; statistic, minimum sample reading of 180 degrees Fahrenheit Population, all chicken meat temperature readings; parameter, minimum temperature of 170 degrees Fahrenheit; sample, four random thermometer readings; statistic, minimum sample reading of 180 degrees Fahrenheit Population, minimum sample reading of 180 degrees Fahrenheit; parameter, all chicken meat; sample, minimum temperature of 170 degrees Fahrenheit; statistic, four random thermometer readings

Answers

Answer:

Population, all chicken meat; parameter, minimum temperature of 170 degrees Fahrenheit; sample, four random thermometer readings; statistic, minimum sample reading of 180 degrees Fahrenheit

Step-by-step explanation:

When dragons on planet Pern lay eggs, the eggs are either green or yellow. The biologists have observed over the years that 32% of the eggs are yellow, and the rest green. Next spring the lead scientist has permission to randomly select 45 of the dragon eggs to incubate. Consider all the possible samples of 45 dragon eggs. What is the usual number of yellow eggs in samples of 45 eggs

Answers

Answer:

The usual number of yellow eggs in samples of 45 eggs is 14.4.

Step-by-step explanation:

For each egg, there are only two possible outcomes. Either they are yellow, or they are not. The probability of an egg being yellow is independent of other eggs, so we use the binomial probability distribution to solve this question.

Binomial probability distribution

Probability of exactly x sucesses on n repeated trials, with p probability.

The expected value of the binomial distribution is:

[tex]E(X) = np[/tex]

32% of the eggs are yellow

This means that [tex]p = 0.32[/tex]

45 eggs

This means that [tex]n = 45[/tex]

What is the usual number of yellow eggs in samples of 45 eggs

[tex]E(X) = np = 45*0.32 = 14.4[/tex]

The usual number of yellow eggs in samples of 45 eggs is 14.4.

Final answer:

In a random sample of 45 dragon eggs on planet Pern, we would typically expect around 14 to 15 eggs to be yellow, based on the given probability of an egg being yellow (which is 32%).

Explanation:

The subject of the question relates to probabilities in statistics. Here, we are given that the chance a dragon's egg on planet Pern is yellow is 32% or 0.32 in decimal form. We are then asked to predict the number of yellow eggs in a group of 45 eggs.

To solve this, we simply multiply the total number of eggs by the notation of the probability:

45 eggs * 0.32 = 14.4

However, you can't have 0.4 of an egg, so we have to round this number to 14 or 15 eggs. Therefore, in a random sample of 45 dragon eggs, we would typically expect around 14 to 15 of them to be yellow assuming that the probability remains constant.

Learn more about Probability here:

https://brainly.com/question/22962752

#SPJ3

According to the National Institute on Drug Abuse, a U.S. government agency, 17.3% of 8th graders in 2010 had used marijuana at some point in their lives. A school official hopes to show the percentage is lower in his district, testing LaTeX: H_0H 0: LaTeX: p=0.173p = 0.173 versus LaTeX: H_aH a: LaTeX: p<0.173p < 0.173. The health department for the district uses anonymous random sampling and finds that 10% of 80 eighth-graders surveyed had used marijuana. Are conditions met for use of the normal model to represent the distribution of sample proportions?

Answers

Answer:

The conditions for use of the normal model to represent the distribution of sample proportion are not met. He should increase the sample size until the conditions are met.

If the test is done anyway, the null hypothesis failed to be rejected.

The conclusion is taht there is not enough evidence to support the claim that the percentage is lower in this district.

Step-by-step explanation:

The conditions for use of the normal model to represent the distribution of sample proportion are not met, as the affirmative responses are less than 10.

[tex]np=80*0.1=8<10[/tex]

If the test of hypothesis is done as if the conditiones were met, we know that the claim is that  the percentage is lower in this district.

Then, the null and alternative hypothesis are:

[tex]H_0: \pi=0.173\\\\H_a:\pi<0.173[/tex]

The significance level is 0.05.

The sample has a size n=80.

The sample proportion is p=0.1.

 

The standard error of the proportion is:

[tex]\sigma_p=\sqrt{\dfrac{\pi(1-\pi)}{n}}=\sqrt{\dfrac{0.173*0.827}{80}}\\\\\\ \sigma_p=\sqrt{0.001788}=0.042[/tex]

Then, we can calculate the z-statistic as:

[tex]z=\dfrac{p-\pi+0.5/n}{\sigma_p}=\dfrac{0.1-0.173+0.5/80}{0.042}=\dfrac{-0.067}{0.042}=-1.578[/tex]

This test is a left-tailed test, so the P-value for this test is calculated as:

[tex]P-value=P(z<-1.578)=0.057[/tex]

As the P-value (0.057) is greater than the significance level (0.05), the effect is  not significant.

The null hypothesis failed to be rejected.

There is not enough evidence to support the claim that  the percentage is lower in this district.

A manufacturer of t-shirts marks a shirt as "irregular" when it has defects such as crooked seams, stains, rips, or holes. A small number of irregular t-shirts are expected as part of the manufacturing process, but if more than 8% of the t-shirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process. In order to test whether his plant is making a higher than expected number of irregular t-shirts, the manager of a plant randomly selects 100 t-shirts and finds that 12 are irregular. He plans to test the hypothesis: H0, P = 0.08, versus Ha, p > 0.08 (where p is the true proportion of irregular t-shirts). What is the test statistic

Answers

Answer:

The test statistic value is 1.474.

Step-by-step explanation:

In this case we need to determine whether the plant is making a higher than expected number of irregular t-shirts.

If more than 8% of the t-shirts manufactured at a plant are classified as irregular, the manager has to do an investigation to try to find the source of the increased mistakes in the manufacturing process..

The hypothesis for this test can be defined as follows:

H₀: The proportion of irregular t-shirts is 8%, i.e. p = 0.08.

Hₐ: The proportion of irregular t-shirts is more than 8%, i.e. p > 0.08.

The information provided is:

n = 100

X = number of irregular t-shirts = 12

Compute the sample proportion as follows:

[tex]\hat p=\frac{X}{n}=\frac{12}{100}=0.12[/tex]

Compute the test statistic as follows:

[tex]t=\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]

  [tex]=\frac{0.12-0.08}{\sqrt{\frac{0.08(1-0.08)}{100}}}\\\\=1.47441\\\\\approx 1.474[/tex]

Thus, the test statistic value is 1.474.

A researcher wanted to test his claim that the mean walking pace of business
travelers is different from that of leisure travelers at the airport. To test his claim he
obtained the following lists of 9 business and 8 leisure travelers. Test his claim at the
.05 = level of significance.
Business
Travelers
42 31 37 45 49 52 43 39 45
Leisure
Travelers
32 29 35 40 38 34 42 33

Answers

Answer:

[tex] t = \frac{42.56-35.375}{\sqrt{\frac{6.327^2}{9} +\frac{4.34^2}{8}}}=2.755[/tex]

The degrees of freedom are given by:

[tex] df=n_1 +n_2-2 =9+8-2= 15[/tex]

Since we have a two tailed test the p value can be calculated like this:

[tex] p_v=2* P(t_{15} >2.755) = 0.0147[/tex]

And since the p value is lower than the significance lvel given of 0.05 we have enough evidence to conclude that we have significant differences between the two groups on this case.

Step-by-step explanation:

We have the following data given:

Business  Travelers

42 31 37 45 49 52 43 39 45

Leisure  Travelers

32 29 35 40 38 34 42 33

For this case we need to begin finding the sample mean and deviations for each group with the following formulas:

[tex]\bar X =\frac{\sum_{i=1}^n X_i}{n}[/tex]

[tex] s=\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}[/tex]

And we got:

[tex] \bar X_1 = 42.56[/tex] represent the sample mean for the Business travelers

[tex]s_1 = 6.327[/tex] represent the sample deviation for the Business travelers

[tex]n_1= 9[/tex] the sample size for the Business travelers

[tex] \bar X_2 = 35.375[/tex] represent the sample mean for the Leisure travelers

[tex]s_2 =4.34[/tex] represent the sample deviation for the Leisure travelers

[tex]n_2= 8[/tex] the sample size for the Leisure travelers

The system of hypothesis for this case are:

Null hypothesis: [tex] \mu_1 =\mu_2[/tex]

Alternative hypothesis: [tex] \mu_1 \neq \mu_2[/tex]

The statistic for this case is given by:

[tex] t =\frac{\bar X_1 -\bar X_2}{\sqrt{\frac{s^2_1}{n_1}+\frac{s^2_2}{n_2}}}[/tex]

And replacing we got:

[tex] t = \frac{42.56-35.375}{\sqrt{\frac{6.327^2}{9} +\frac{4.34^2}{8}}}=2.755[/tex]

The degrees of freedom are given by:

[tex] df=n_1 +n_2-2 =9+8-2= 15[/tex]

Since we have a two tailed test the p value can be calculated like this:

[tex] p_v= 2*P(t_{15} >2.755) = 0.0147[/tex]

And since the p value is lower than the significance lvel given of 0.05 we have enough evidence to conclude that we have significant differences between the two groups on this case.

5. Melanie scored 20/25 on her quiz. What percent is this equal to? *

Answers

Answer:

0.8 or 80%

Step-by-step explanation:

To easily find percents, divide the numerator with the denominator. Or, first you can simplify the fraction first.

20/25 can be divided by 5. Which is 4/5.

4/5=0.8

So, the answer is 80%

Answer:

80%

Step-by-step explanation:

[tex]\frac{20}{25} = \frac{4}{5}[/tex]

To find the percentage, multiply by 100:

[tex]\frac{4}{5} * 100 = 80[/tex]

Jane wants to buy a movie that costs $15.49. She has $8.75. How much more money does Jane need to buy the movie?

Answers

Answer:

$6.74

Step-by-step explanation:

Subtract 15.49 and 8.75

Answer: 6.74.

Step-by-step explanation: I took the quiz before!

Hope this helps! (✪ ω ✪)

A math teacher claims that she has developed a review course that increases the scores of students on the math portion of a college entrance exam. Based on data from the administrator of the​ exam, scores are normally distributed with mu equalsμ=522522. The teacher obtains a random sample of 20002000 ​students, puts them through the review​ class, and finds that the mean math score of the 20002000 students is 527527 with a standard deviation of 110110. Complete parts​ (a) through​ (d) below. ​(a) State the null and alternative hypotheses. Let muμ be the mean score. Choose the correct answer below. A. Upper H 0 : mu equals 522H0: μ=522​, Upper H 1 : mu not equals 522H1: μ≠522 B. Upper H 0 : mu less than 522H0: μ<522​, Upper H 1 : mu greater than 522H1: μ>522 C. Upper H 0 : mu greater than 522H0: μ>522​, Upper H 1 : mu not equals 522H1: μ≠522 D. Upper H 0 : mu equals 522H0: μ=522​, Upper H 1 : mu greater than 522

Answers

Answer: D

H0: μ=522

H1: μ>522

Step-by-step explanation:

The null hypothesis (H0) tries to show that no significant variation exists between variables or that a single variable is no different than its mean. While an alternative Hypothesis (Ha) attempt to prove that a new theory is true rather than the old one. That a variable is significantly different from the mean.

So, for this case;

The null hypothesis is that the mean score equals to 522

H0: μ=522

The alternative hypothesis is that the mean score is greater than 522.

H1: μ>522

The correct answer is D. [tex]Upper H_0: = 522, Upper H_1 > 522[/tex].

In this scenario, the math teacher is claiming that her review course increases the scores of students on the math portion of a college entrance exam. Therefore, the null hypothesis [tex](H_0)[/tex]  should represent the claim that there is no increase in the mean score, which would be that the mean score is equal to the population mean of 522. The alternative hypothesis [tex](H_1)[/tex]   should represent the teacher's claim that the mean score has increased, which would be that the mean score is greater than 522.The null hypothesis is a statement of no effect or no difference and serves as the baseline for testing. The alternative hypothesis is what we aim to support; it is a statement that there is an effect or a difference. In this case, we are testing whether the mean score of students after taking the review course is greater than the population mean.Therefore, the correct hypotheses are:- Null Hypothesis [tex](H_0): = 522[/tex] , indicating no increase in the mean score.- Alternative Hypothesis [tex](H_1): > 522[/tex] , indicating an increase in the mean score.This is a one-tailed test because we are only interested in whether the mean score has increased, not whether it has changed at all (which would require a two-tailed test).

Help whats 2+2 please i cant figure it out its baby two right

Answers

2 + 2 =4 is four tgvjixyi9

Answer:

It’s 4 or fish

Step-by-step explanation:

The net below represent a container. What solid figure does it show?
How many vertices does the container have?

Answers

6 vertices not sure what the shape is tho sorry

The solid figure that is shown by the net would be a Rectangular prism.

The number of vertices would be 8 vertices.

How to describe a rectangular prism?

A rectangular prism is a 3D shape with six faces, eight vertices, and twelve edges. It is a type of polyhedron, which is a solid figure with flat faces and straight edges.

The net given is a rectangular prism because the dashed lines show that the sides would fold up along with the triangles to form a rectangular prism.  

Find out more on vertices at https://brainly.com/question/30397773

#SPJ2

A brokerage charges ? regardless of whether an investor buys or sells assets, and ? are incurred with every transaction

Answers

Answer:

Yes, that's true.

Step-by-step explanation:

A brokerage fee is the commission paid to a salesperson or broker for selling insurance or securities, respectively. The amount of this fee is usually calculated as a percentage of the transaction price, though it may be a flat fee.

brokerage fee compensates a broker for executing a transaction. It is usually, but not always, a percentage of the transaction value. In finance, stockbrokers most often come to mind, but real estate agents and business brokers frequently charge brokerage fees

Answer:

A brokerage charges  brokerage account fees  regardless of whether an investor buys or sells assets, and trade commissions  are incurred with every transaction.

1. Write an expression that represents the area of a rectangle given that the Length = (x+3) and the width = (3x + 4).

2. The area of a rectangle is 28x2 – 13xy – 6y2 square units. If the length of the rectangle is 7x + 2y units, then find the breadth of the rectangle, hence find the perimeter of the rectangle

Answers

Answer:

(7x+2y)- length (4x-3y)- width

22x-2y is the perimeter.

Step-by-step explanation:

The speed of pickup of ride sharing services like Uber and Lyft seems to have surpassed that of ambulance services. The mean response time of ambulances across the United States is 15.3 minutes with a standard deviation of 12.8 minutes. For ride sharing services, the mean pick-up time across the United States is 8 minutes with a standard deviation of 5.2 minutes. Based on these estimates, which of the following gives the standard deviation of the sampling distribution of the difference in the sample means for samples of 30 ambulance rides and 40 ride sharing rides (Ambulance – Ride Sharing)?

Answers

Answer:

The correct answer is (C).  

Because the sample sizes are less than 10% of their respective population sizes, the standard deviation of the difference in sample means is approximately≈2.912 minutes.

 

​  

Step-by-step explanation:

Answer:

Step-by-step explanation:

The correct answer is (C).

Because the sample sizes are less than 10% of their respective population sizes, the standard deviation of the difference in sample means is approximately \sqrt{\frac{s_1^2}{n_1}+\frac{s_2^2}{n_2}} = \sqrt{\frac{12.8^2}{30}+\frac{5.2^2}{40}} \approx 2.912

n

1

s

1

2

​ +

n

2

s

2

2

​ =

30

12.8

2

​ +

40

5.2

2

​ ≈2.912 minutes.

3x^2 + 18x + 27 = 0 can you solve for x

Answers

Answer:

     3x^2 + 18x + 27 = 0

<=> 3(x^2 + 6x + 9) = 0

<=> 3(x + 3)^2 = 0

<=> x = -3

Hope this helps!

:)

The equation y= 2x represents a set of data.
Which statement is NOT true?

Answers

Answer:

2 is an initial value

tell me if its right because i garuntee it is

Which of the following is the equation of a direct variation that has a constant of variation equal to -1/2?

A. y= x- 1/2
B. -1/2 y=x
C. y= -2x
D. y= -1/2x

Answers

The answer is C. Cause the other ones don’t make sense

I think it is c. y= -2x hope you have a good day!

a box contains 8 red balls, 5 brown balls, 4 purple balls, and 3 green balls. what is the probability that a purple ball will be selected from the box after a red ball is taken out and not replaced?

Write the probability as a percent. Round to the nearest tenth of a percent as needed.

Answers

The probability is 20%

Compute: 3:40 - 1:55

Answers

Answer:

 0 days 3 hours 40 minutes 0 seconds

- 0 days 1 hours 55 minutes 0 seconds

= 0 days 1 hours 45 minutes 0 seconds

= 0.0729167 days

= 1.75 hours

= 105 minutes

= 6,300 seconds

Step-by-step explanation:

Final answer:

To calculate the difference between given times, convert them into minutes and subtract. The result will be the time difference in minutes.

Explanation:

Compute: 3:40 - 1:55

To compute the difference between 3:40 and 1:55, you need to subtract the two times. First, convert both times into minutes: 3:40 = 3 x 60 + 40 = 180 + 40 = 220 minutes, and 1:55 = 1 x 60 + 55 = 60 + 55 = 115 minutes. Then, subtract 115 from 220 to get the result.

The difference between 3:40 and 1:55 is 105 minutes.

3. Erin's soccer team has won 17 of
their 20 games this season. What is
the probability that they will win their
next game?

Answers

Answer:

They have a 85% chance of winning their next game.

Step-by-step explanation:

100÷20 = 5

17×5=85

So, they have a 85% chance of winning their next game.

Hope This helped!!!!! :)

A dietitian wants to know the average time spent on breakfast in a primary school. The dietitian randomly samples 16 students and finds that the average is 15.8 minutes with a standard deviation of 2.31 minutes. Assume that the distribution of the time spent on the breakfast is normally distributed. The dietitian finds a 90% confidence interval for this sample is (14.788, 16.812) Flag question Select one or more:_________. a. The margin of error is 1.012. b. The margin of error is 2.024 c. The margin of error is 0.950 d. We believe that the true mean time spent on breakfast in this primary school is between 14.788 and 16.812 minutes. e. If we take many other samples from this population, 90% of them will have a sample mean that is between 14.788 and 16.812. f. There is a 90% chance that the true mean is between 14.788 and 16.812 minutes.

Answers

Answer: is their any picture? or an example?

P
Q
R
S
T
-10
-8
6
4
2
0
2
4
6
Find the midpoint of PS.

Answers

PSPSPSPSPSSPSPSPSPSPS

What is the mean of 3, 2, 26, 9

Answers

Answer:

10

Step-by-step explanation:

3+2=5+26=31+9=40/4=10

Step-by-step explanation:

When finding mean, you have to add up all of the number and divide that answer by the number of numbers used.

3 + 2 + 26 + 9 = 40

Now, we will divide 40 by 4 because there are 4 numbers.

40 / 4 = 10

So, the mean of the set is 10.

Other Questions
30 points!!!im looking at number 5 right now. i dont know what -2x means. can someone show me an example of how you do it Read the two excerpts from Weve Got a Job by Cynthia Levinson.Audrey talked quietly with her mother and father. As far as she could tell, she was the youngest child there, and she didnt know anyone else. "My girlfriend . . . was to demonstrate, too, that day, she said. "I had expected to see her. But she wasnt there. Nevertheless, Audrey said, "I didnt have any fear.*****Meanwhile, Wash had arrived at Kelly Ingram Park to watch. "[W]e saw those people willingly turn themselves over to the police . . ., he said. His reaction: "Wow, they must be crazy. Experience had taught Wash that "the police was vicious murderers. He knew how much pain they could inflict on young black bodiesWhich statement best represents how the march affected Audrey and Wash?A. Although Audrey was young, she was not afraid, and Wash thought a person must be crazy to not have a fear of the police.B. Although Wash believed in the Movement, he knew his mind and body could not handle jail, while Audrey knew that she would find her girlfriend there.C. Neither Audrey nor Wash felt that the Movement was important for the people in the community.D. Both Wash and Audrey knew that by the end of the day they would be resting in a jail cell with many others. A 80-kg person sits on a 2.7kg chair. Each leg of the chair makes contact with the floor on a circle that is 1.3 cm in diameter. Find the pressure exerted on the floor by each leg of the chair, assuming that the weight is evenly distributed. An oven mitt is made of a material that is a poor thermal conductor.Which is the most likely reason that the material makes a good oven mitt?A: it is made mostly of waterB: it lacks electronsC: it is made of tightly packed particlesD: its electrons do not move freely British laws or actions that the American colonists thought were unfair Need help with this ASAP. Anything is appreciated:)) Lake Incorporated purchased all of the outstanding stock of Huron Company paying $967,000 cash. Lake assumed all of the liabilities of Huron. Book values and fair values of acquired assets and liabilities were: Book Value Fair Value Current assets (net) $ 130,900 $ 124,200 Property, plant, equipment) 619,000 757,000 Liabilities 151,700 177,000 Lake would record goodwill of: Multiple Choice $368,800. $0. $262,800. $85,800. Chen has an MP3 player called the Jumble. The Jumble randomly selects a song for the user to listen to. Chen's Jumble has 444 classical songs, 333 rock songs, and 222 rap songs on it. Chen is going to listen to 360360360 songs.What is the best prediction for the number of times Chen will listen to a classical song? Which examples are independent clauses? Select all that apply.over the roofit sailed through the windowshe came insidejumped incredibly highthe juicy orangeMartin climbed the mountain Which sentence uses hyphens correctly? O A. The pizza place- the best in town- closed early due to snow. O B. The 3-year-old girl loved the teddy bear dearly. C. The cell phone-although new-no longer works. D. He felt no-need to inform work that he would not be in today. Explain the difference between sea anemones and jellyfish. Write a short excerpt from the Gettysburg Address that shows how Lincoln chose words to connect his speech to the Declaration of Independence. Then explain why you think he wanted to connect his address to the Declaration Which line best shows that the speaker is forgiving?I Have A White Rose To Tendby Jose MartiI have a white rose to tendIn July as in January;I give it to the true friendWho offers his frank hand to me.And for the cruel one whose blowsBreak the heart by which I live,Thistle nor thorn do I give:For him, too, I have a white rose. NEED HELP WITH TRIG please show work as i am trying to learn the material i'm really puzzled. its soh cah toa but i don't remember how to do it the boa constrictor in the Everglades is an example of what species that is impacting local species An English teacher needs to pick 9 books to put on his reading list for the next school year, and he needs to plan the order in which they should be read. He has narrowed down his choices to 19 novels, 22 plays, and 22 nonfiction books. If he wants to include an equal number of novels, plays, and nonfiction books, how many different reading schedules are possible? Express your answer in scientific notation rounding to the hundredths place. #2 Find the slope given the points (6,-12) and (15,-3)* Match each type of business with its purpose.Non-profitcorporation?To make profit for itsownerSoleproprietorship?.To make dividends for itsstockholdersPubliccorporation?To benefit a special cause The filament of a certain lamp has a resistance that increases linearly with temperature. When a constant voltage is switched on, the initial current decreases until the filament reaches its steady-state temperature. The temperature coefficient of resistivity of the filament is 4 times 10-3 K-1. The final current through the filament is one- eighth the initial current. What is the change in temperature of the filament The Pew Research Center reported in 2018 that 68% of U.S. adults rated "reducing health care costs" as a national priority. This year a survey is conducted with a national sample of 1,505 U.S. adults selected by a combination of landline and cell phone random digit dials. This year's survey finds that 70% of the sample says that "reducing health care costs" is a national priority.We test the following hypotheses:H0: The proportion of U.S. adults this year who rate "reducing health care costs" as a national priority is still 0.68.Ha: The proportion of U.S. adults this year who rate "reducing health care costs" as a national priority is greater than 0.68.The P-value is 0.045. At a 5% significance level, we would reject the null hypothesis and concluded that the proportion of U.S. adults this year who rate "reducing health care costs" as a national priority is greater than 0.68.Explain the P-value in the context of this issue. Steam Workshop Downloader