Scientists at the Hopkins Memorial Forest have been collecting environmental data for more than 100 years. Sulfate content in water samples from Birch Brook is known to be 7.38mg/L with a standard deviation of 1.60mg/L. If 10 students measure the sulfate in their samples to together estimate the mean, what is the probability that they get a sampling error of greater than 1.0 mg/L? What assumptions do we need to make to calculate that value?

Answers

Answer 1

Answer:

The probability that they get a sampling error of greater than 1.0 mg/L is 0.04.

To calculate this value, I assume that the samples are randomly collected

Step-by-step explanation:

Sampling error can be calculated using the formula

[tex]\frac{t*s}{\sqrt{n}}[/tex]  where

t is the statistic of the probability getting the standard errors is the standard deviation (1.60mg/L)n is the sample size (10)

For the sampling error of 1.0mg/L we have

[tex]1=\frac{t*1.60}{\sqrt{10}}[/tex]    

Solving for t we have t≈1.976

Then the probability that they get a sampling error of greater than 1.0 mg/L is

P(t>1.976) ≈ 0.04.

In other words, we are 96% confident that the sampling error is within 1.0 mg/L.

To calculate this value, I assume that the samples are randomly collected.


Related Questions

Topic: Associative, Commutative, and Distributive Properties

Which property is not used to simplify the following expression?

2*(x+5)+7x=(2x+10)+7x
=(10+2x)+7x
=10 +(2x+7x)
=10 + 9x
=9x + 10

A. associative property of addition

B. commutative property of addition

C. distributive property

D. commutative property of multiplication

Answers

Answer:

D

Step-by-step explanation:

cumulative property of multiplication

Final answer:

The distributive property is not used in the simplification of the expression 2×(x+5)+7x. The expression is simplified using the associative and commutative properties of addition.

Explanation:

The property that is not used to simplify the following expression 2×(x+5)+7x=(2x+10)+7x=(10+2x)+7x=10 +(2x+7x)=10 + 9x=9x + 10 is C. distributive property. Let's look at how each property is applied in the simplification:

Associative property of addition: This property is used when the expression goes from 2×(x+5)+7x to (2x+10)+7x and again from (10+2x)+7x to 10 +(2x+7x).

Commutative property of addition: This property is used when the terms 2x and 10 are rearranged as (10+2x) and also when the final step changes 10 + 9x to 9x + 10.

The distributive property is not used at any step in this problem. This property would involve multiplication across a sum, such as a(b + c) = ab + ac, which is not seen in the simplification process.

The commutative property of multiplication is also not used, as there is no rearrangement of multiplication terms.

(a) State the Cauchy-Schwarz inequality in an equation, in words, and in a planar sketch. (b) Use part (a) to give all solutions to the following. Let x E Rn: arg max ļaTa 2 subject to |c11-1

Answers

Complete question

The complete question is shown on the first uploaded image

Answer:

The solution and the explanation is on the second third and fourth uploaded image

Which of the following functions are solutions of the differential equation y+4y+4y=0? A. y(x) =e^-2x B. y(x) = e^+22 C. y(x) = xe^-2x D. y(x) = -2x E. y(x) = 0 F. g(x) = x^2e^-2x

Answers

Final answer:

Options A, C, and F are solutions to the differential equation.

Explanation:

The given differential equation is y''+4y'+4y=0.

To check which of the given functions are solutions of the differential equation, we substitute each function into the equation and check if it satisfies the equation.

By substituting each function and simplifying, we find that options A, C, and F are solutions to the differential equation.

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According to the empirical rule, if the data form a bell-shaped normal distribution, __________ of the observations will fall within two standard deviations around the mean.

Answers

Answer:

95%

Step-by-step explanation:

The empirical rule states that if data follows normal distribution then the percentage of observations falls within one, two and three standard deviation around the mean are

i) 68% falls within one standard deviation

ii) 95% falls within two standard deviation

iii) 99.7% falls within three standard deviation.

Hence 95% of the observations will fall within two standard deviations around the mean if the data follows normal distribution.

According to the empirical rule, approximately 95 percent of observations in a bell-shaped normal distribution fall within two standard deviations of the mean.

According to the empirical rule, if the data form a bell-shaped normal distribution, approximately 95 percent of the observations will fall within two standard deviations around the mean. This statistical concept is an important part of descriptive statistics and is crucial when studying the Normal or Gaussian probability distribution.

In a normal distribution, the data is symmetric around the mean, and as dictated by the empirical rule, about 68% of the data lies within one standard deviation, while approximately 95% lies within two standard deviations, and over 99% within three standard deviations of the mean.

The curve given by x=sin(t),y=sin(t+sin(t)) 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=f(x) without t′s.

Answers

Answer:

y = 0

y =2x

Step-by-step explanation:

Given parametric equations:

x (t) = sin (t)

y (t) = sin (t + sin (t))

The slope of the curve at any given point is given by dy / dx we will use chain rule to find dy / dx

(dy / dx) * (dx / dt) = (dy / dt)

(dy / dx) = (dy / dt) / (dx / dt)

Evaluate dx / dt and dy / dt

dx / dt = cos (t)

dy / dt = cos (t + sin (t)) * (1+cos (t))

Hence,

dy / dx = (1+cos(t))*cos(t + sin (t))) / cos (t)

@Given point (x,y) = 0 we evaluate t

0 = sin (t)

t = 0 , pi

Input two values of t and compute dy / dx

@ t = 0

dy / dx = (1 + cos (0))*cos (0 + sin (0))) / cos (0)

dy / dx = (1+1)*(1) / (1) = 2 @ t = 0

@t = pi

dy / dx = ( 1 + cos (pi))* cos (pi + sin (pi)) / cos (pi)

dy / dx = (1-1) * (-1) / (-1) = 0 @ t = pi

The corresponding gradients are 0 and 2 in increasing order and their respective equations are:

y = 2x

y = 0

The equation of the two tangent lines at the point (x,y) = (0,0) in order of increasing slope are; y = 0 and y = 2x

We are given the parametric equations of the curve as;

x = sin(t)

y = sin(t + sin(t))

Now, since we want to find slope, the we need to find dy/dx from;

dy/dx = (dy/dt) ÷ (dx/dt)

Thus;

dx/dt = cos(t)

Using chain rule;

dy/dt = cos (t + sin(t)) × (1 + cos(t))

Thus;

dy/dx = [cos (t + sin(t)) × (1 + cos(t))]/(cos(t))

At (0, 0), we have;

0 = sin(t)   ---(1)

0 = sin(t + sin(t))   ---(2)

From eq (1), values of t that makes the function 0 are;

0 and π

Thus;

At t = 0;

dy/dx =  [cos (0 + sin(0)) × (1 + cos(0))]/(cos(0))

dy/dx = (1 + 1)/1

dy/dx = 2

At t = π;

dy/dx =  [cos (π + sin(π)) × (1 + cos(π))]/(cos(π))

dy/dx = 0

Using the point slope form; y - y₁ = m(x - x₁)

At m = 2, we have;

y - 0 = 2(x - 0)

y = 2x

At m = 0, we have;

y - 0 = 0(x - 0)

y = 0

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Suppose that Britain pegs the pound to gold at six pounds per ounce, whereas the exchange rate between pounds and U.S. dollars is $5 = £1. What would an ounce of gold be worth in U.S. dollars?

Answers

Final answer:

Given the exchange rate of $5 = £1 and the conversion rate of 6 pounds per ounce of gold, the equivalent amount for an ounce of gold would be $30.

Explanation:

In this scenario, given that the exchange rate between pounds and U.S. dollars is $5 = £1 and the conversion rate of pound to gold is six pounds per ounce, we want to find the value of an ounce of gold in U.S. dollars. Firstly, we need to establish how many pounds per ounce of gold, which is set at six pounds. With the currency exchange rate, $5 equals one pound. Therefore, to find the value in dollars, simply multiply these two rates together. That comes to 6 (pounds per ounce of gold) * 5 (dollars per pound) = $30. Hence, an ounce of gold would be worth $30.

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Without calculation, decide if each of the integrals below are positive, negative, or zero. Let W be the solid bounded by z=sqrt(x2+y2) and z=2.1. ∭(z−2)dV2. ∭e−xyzdV3. ∭(z−sqrt(x2+y2))dV

Answers

Answer:

1) ∭(z−2) dV  negative.

2) ∭e^{−xyz} dV  positive.

3) ∭( z-\sqrt{x²+y²})  positive.

Step-by-step explanation:

From Exercise we have:

z=\sqrt{x²+y²}

z=2

⇒2=\sqrt{x²+y²}

4=x²+y²

Therefore, we get that  the solid bounded by:

\sqrt{x²+y²}≤z≤2

4=x²+y²

1) From initial condition we have that

\sqrt{x²+y²}≤z≤2

⇒ 2-z≤0

Therefore, we get that the triple integral is

∭(z−2) dV  negative.

2) We know that e^{-xyz} is always positive number.

Therefore, we get that the triple integral is

∭e^{−xyz} dV  positive.

3) From initial condition we have that

\sqrt{x²+y²}≤z≤2

⇒ z-\sqrt{x²+y²}>0

Therefore, we get that the triple integral is

∭( z-\sqrt{x²+y²})  positive.

Final answer:

The given triple integrals, when evaluated over the defined region, result in the first integral being zero, while the second and third integrals yield positive values. This determination is made based on the properties of the integrand over the given region, without resorting to complete calculation.

Explanation:Triples Integral Evaluation

The question involves the evaluation of triple integrals over a given region W bounded by the surfaces z = sqrt(x^2 + y^2) and z = 2.1. Without explicit calculations, we can determine the sign of the integrals by assessing the integrand function over the specified region.

∭(z − 2)dV: Here, the integral will be zero as over the specified region W, z varies from sqrt(x^2 + y^2) to 2.1 which implies for some portions of W, z-2<0 and for some portions, it's >0. Hence, it cancels each other.∭e^−xyz dV: It will be a positive value since exponential of a number is always positive. ∭(z − sqrt(x^2 + y^2))dV: This integral will be positive since over the region W, z ranges from sqrt(x^2 + y^2) to 2.1, and hence z - sqrt(x^2 + y^2) is always greater than 0.

Therefore, the first integral would yield zero, while the second and third integrals would yield positive values.

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An ice cream cone is filled with vanilla and chocolate ice cream at a ratio of 2:1. If the diameter of the cone is 2 inches and the height is 6 inches, approximately what is the volume of vanilla ice cream in the cone? (round to nearest tenth) A) 1.0 in3 B) 2.1 in3 C) 4.2 in3 D) 6.3 in3

Answers

Answer:

D. 6.3 in^3

Step-by-step explanation:

V= 1/3 (3.14)(r^2)(h)

V= 1/3 (3.14) (1^2)(6)

V=6.3 in^3

Answer:

c

Step-by-step explanation: it was on usa test prep and the answer that was there was wrong.

Let A be a 5 x 3 matrix, let y be a vector in R3, and let z be a vector in R5. Suppose Ay = z. What fact allows you to conclude that the system Ax = 5z is consistent?

Answers

Answer:

Step by step approach is as shown

Step-by-step explanation:

Consider the system Ax = 5z .............(1)Recalling that z = AySubstitute (Ay) for z in equation (1)therefore, Ax = 5(Ay) ....................... (2) Hence the equation can also be written as Ax = A(5y) ................ (3)

recalling from commutative law that A + B = B + A and since A is a scalar, and from scalar multiplication of matrix.

From equation (3) ; Ax = A(5y), it implies that x = 5y from comparison and as such if we compare with equation (2) where z = Aytherefore equation (2) can then be written as Ax = 5z, since there is consistency as such the the equation will also have a solution.

Systematic Sampling Technique is used to select 5 numbers between 1 and 200. The first selected number is 12. What should be next four numbers?

Answers

Answer:  52, 92 , 132, 172

Step-by-step explanation:

A systematic random sampling is a random sampling technique in which a sample from a large population are chosen according to a random beginning point and a fixed periodic interval (k).

Given : Systematic Sampling Technique is used to select 5 numbers between 1 and 200.

⇒ Population size : N=200

Required Sample size  : n=5

Since , Sampling interval is given by :-

[tex]k=\dfrac{N}{n}[/tex]

⇒ [tex]k=\dfrac{200}{5}[=40/tex]

If the first selected number is 12, then the next four numbers would be :

(12+K) , (12+2k) , (12+3k) , (12+4k)

Put value of k , we get

(12+40) , (12+2(40)) , (12+3(40)) , (12+4(40)) =(52, 92 , 132, 172)

Hence, the  next four numbers are : 52, 92 , 132, 172

The formula for a buffer solution contains 1.24% w/v of boric acid. How many milli-liters of a 5% w/v boric acid solution should be used to obtain the boric acid needed in preparing 1 liter of the buffer solution?

Answers

Answer: 248mL

Step-by-step explanation:

Given:

Concentration of buffer solution Cs = 1.24%w/v of boric acid

Concentration of boric acid solution Cb = 5 % w/v boric acid

For 1 liter of buffer solution, the weight of boric acid needed is:

mb = 1 × 1.24 = 1.24 unit weight

mb = Cb × Vb .....1

Cb = concentration of boric acid solution.

Vb = volume of boric acid solution needed.

mb = weight of boric acid needed.

From equation 1.

Vb = mb/Cb

Vb = 1.24/5

Vb = 0.248L

Vb = 248mL

248 milli-liters of a 5% w / v boric acid solution should be used to obtain the boric acid needed.

Since the formula for a buffer solution contains 1.24% w / v of boric acid, to determine how many milli-liters of a 5% w / v boric acid solution should be used to obtain the boric acid needed in preparing 1 liter of the buffer solution, the following calculation must be performed:

1000 milliliters = 1 liter 5 = 1000 1.24 = X 1.24 x 1000/5 = X 1240/5 = X 248 = X

Therefore, 248 milli-liters of a 5% w / v boric acid solution should be used to obtain the boric acid needed.

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The water content of soil from a borrow site is normally distributed with a mean of 14% and a standard deviation of 2.5%. What is the probability that a sample taken from the site will have a water content above 16% or below 12%?

Answers

The probability  that a sample taken from the site will have water content above 16% or below 12% is 0.3862.

Given that,

Mean = µ

= 14%

= 0.14

Standard deviation = σ

= 2.5%

= 0.025

[Using standard normal table]

16% or 12% = 0.16 or 0.12

P(X < 0.16 or X > 0.12)

Using standard normal table,    

To see the z value -0.9 in the row and 0.06 in the column of the standard normal table the cumulative probability of z = -0.96  is = 0.1685

To see the z value 0.7 in the row and 0.08 in the column of the standard normal table the cumulative probability of z = 0.78  is = 0.7823

[tex]P(X < 0.6\ or \ x > 0.12)=1-[P(0.16 < X < 0.12)][/tex]

[tex]=1-{P[\frac{0.16-0.142}{0.023} < \frac{x-\mu}{\sigma} < \frac{0.12-0.142}{0.023}]}[/tex]

[tex]= 1-[P(0.78 < z < -0.96)][/tex]

[tex]= [P(z < -0.96)-P(z < 0.78)][/tex]

[tex]=1-(0.1685-0.7823)[/tex]

[tex]= 1-0.6138[/tex]

[tex]P(X < 0.16 \ or \ X > 0.12)=0.3862[/tex]

Therefore, the probability  that a sample taken from the site will have water content above 16% or below 12% is 0.3862.

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Final answer:

The probability that a random sample’s water content will be higher than 16% or lower than 12% is calculated by converting the values to Z-scores and then using the standard normal distribution's cumulative probability. The values from a Z-table or calculator are used to determine this probability.

Explanation:

The subject of this question is Probability and Statistics, specifically related to the normal distribution. In this scenario, the water content of soil from a borrow site is normally distributed with a mean (μ) of 14% and a standard deviation (σ) of 2.5%.

To find the probability of the soil having a water content above 16% or below 12%, we first need to calculate the Z-scores for these values. The Z-score represents how many standard deviations an element is from the mean. It is calculated as (X - μ)/σ.

For X = 16%, Z = (16 - 14) / 2.5 = 0.8

For X = 12%, Z = (12 - 14) / 2.5 = -0.8

Using a Z-table or a calculator function that outputs standard normal probabilities, we would find that P(Z > 0.8) or P(Z < -0.8). By convention, Z-tables only give values as P(Z < z), for z > 0, so to find P(Z > 0.8), we can do 1 - P(Z < 0.8). Same for P(Z < -0.8).

As such, the desired probability is the sum of these two probabilities.

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Suppose a parallelogram has sides of length a and b. Is this enough information to compute the area of the parallelogram? If not, what additional information is required?

Answers

Answer:

No. it's not enough

Step-by-step explanation:

1) No. it's not enough

2) To compute the area of a parallelogram it's necessary the height of the parallelogram, i.e. a perpendicular line segment from the base up to its parallel side.

3) Because a parallelogram is made up by two triangles and the area of it is calculated using the height. Then to cover the area of a parallelogram it's mandatory to calculate the height, the perpendicular distance between their horizontal sides.

Final answer:

No, the lengths of the sides of a parallelogram alone are not enough to compute its area. Additional information, such as the length of the perpendicular distance between the sides, is needed to calculate the area.

Explanation:

No, the lengths of the sides of a parallelogram alone are not enough to compute its area. To calculate the area of a parallelogram, you need two pieces of information: the length of one of its sides and the length of the corresponding altitude (or height), which is the perpendicular distance between the side and the opposite side. With just the lengths of a and b, we don't know the height, so we can't calculate the area.



To find the area of a parallelogram, you can use the formula: Area = base x height. The base is one of the side lengths, and the height is the length of the perpendicular from the base to the opposite side.



For example, if side a is the base, the height is the distance between side a and the opposite side, which can be found by drawing a perpendicular line. Once you know the height, you can calculate the area using the formula: Area = a x height.

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Show that each of these conditional statements is a tautology by using truth tables.

a) (p ∧ q) → p
b) p → (p ∨ q)
c) ¬p → (p → q)
d) (p ∧ q) → (p → q)
e) ¬(p → q) → p f ) ¬(p → q) → ¬q

Answers

Final answer:

By using truth tables, we can prove that given conditional statements are tautologies. The logic used in the example can also be applied to other statements. Every possible combination of truth values for the components of a tautology yields a true statement.

Explanation:

To show that these conditional statements are tautologies, we can generate truth tables for each one. Tautologies are logical statements that are always true regardless of the truth values of their variable components.

For example, let's examine the statement (p ∧ q) → p:

When both p and q are true, the whole statement is true since 'true AND true' is true, and 'true implies true' is also true.When p is true and q is false, the 'AND' clause yields a false, but because 'true implies false' is still true, the statement remains true.When p is false (regardless of q's value), the 'AND' clause is false, as is the p in the 'implies' clause. However, 'false implies false' is true, and overall, the statement is also true.

This logic can similarly be applied to the remaining statements to prove that they're tautologies.

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The diameter of a brand of tennis balls is approximately normally distributed, with a mean of 2.63 inches and a standard deviation of 0.03 inch. If you select a random sample of 9 tennis balls,

a. What is the sampling distribution of the mean?
b. What is the probability that the sample mean is less than 2.61 inches?
c. What is the probability that the sample mean is between 2.62 and 2.64 inches?
d. The probability is 6-% that the sample mean will be between what two values symmetrically distributed around the population mea

Answers

Answer:

a)  sample mean = 2.63 inches

     sample standard deviation = [tex]\frac{standard \hspace{0.15cm} deviation}{\sqrt{n} } = \frac{0.03}{\sqrt{9} } = \frac{0.03}{3} = 0.01[/tex]

b)  P(X < 2.61) = 0.0228

c.) P(2.62 < X < 2.64)  = 0.6827

d.)  Therefore 0.06 = P(2.6292 < X < 2.6307)

Step-by-step explanation:

i) the diameter of a brand of tennis balls is approximately normally distributed.

ii) mean  = 2.63 inches

iii) standard deviation = 0.03 inches

iv) random sample of 9 tennis balls

v) sample mean = 2.63 inches

vi) sample standard deviation = [tex]\frac{standard \hspace{0.15cm} deviation}{\sqrt{n} } = \frac{0.03}{\sqrt{9} } = \frac{0.03}{3} = 0.01[/tex]

vii) the sample mean is less than 2.61 inches = P(X < 2.61) = 0.0228

viii)the probability that the sample mean is between 2.62 and 2.64 inches

     P(2.62 < X < 2.64)  = 0.6827

ix) The probability is 6-% that the sample mean will be between what two values symmetrically distributed around the population measure

  Therefore 0.06 = P(2.6292 < X < 2.6307)

a) The sampling distribution of the mean is 2.63 inches and sample standard deviation = 0.01

b)  P(X < 2.61) = 0.0228

c) P(2.62 < X < 2.64)  = 0.6827

d)  0.06 = P(2.6292 < X < 2.6307)

Let's solve this step by step:

Step 1: The diameter of a brand of tennis balls is approximately normally distributed.

Given:

Mean  = 2.63 inches

Standard deviation = 0.03 inches

For random sample of 9 tennis balls

Step 2: Sample mean = 2.63 inches

Sample standard deviation = [tex]\frac{\text{standard deviation}}{\sqrt{n} } =\frac{0.03}{\sqrt{9} } =\frac{0.03}{3} =0.01[/tex]

Step 3: The sample mean is less than 2.61 inches = P(X < 2.61) = 0.0228

Step 4: The probability that the sample mean is between 2.62 and 2.64 inches = P(2.62 < X < 2.64)  = 0.6827

Step 5: The probability is 6-% that the sample mean will be between what two values symmetrically distributed around the population measure

Therefore 0.06 = P(2.6292 < X < 2.6307)

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A sample of 60 women is obtained, and their heights ( in inches ) and pulse rates ( in beats per minute ) are measured. The linear correlation coefficient is 0.234 and the equation of the regression line is ^y= 17.5 + 0.850x, where x represents height. The mean of the 60 heights is 63.4 in and the mean of the 60 pulse rates is 75.6 beats per minute. Find the best predicted pulse rate of a woman who is 74 inches tall. Use a significance level of a=0.01.

Answers

Answer:

The best predicted pulse rate of a woman who is 74 inches tall is 80.4 (beats per minute).



Step-by-step explanation:

The best predicted pulse rate of a woman who is 74 inches tall is obtained below:

Let x denotes height (in inches) and y denotes pulse rates (in beats per minute).

From the information, the regression equation is, the total number of women is 60 and the linear correlation coefficient between height and pulse rates is 0.234 and the mean of heights is 63.4 and the mean of pulse rates is 75.6. The estimated regression line is

^y= 17.5 + 0.850x

     The required best predicted pulse rates is,

      =17.5 + (0.850×74)

=17.5 + 62.9

=   80.4  beats per minute

Construct a frequency distribution and a relative frequency distribution for the light bulb data with a class width of 20, starting at 800. Copy and paste your distribution tables here. 2. Construct a histogram based on this frequency distribution table for the light bulb data. Copy and paste your histogram here. Describe the shape of the histogram. (Is it unimodal, bimodal, skewed, etc.?) skewed 3. Now, construct a frequency distribution table and a relative frequency distribution table for the light bulb data with a class width of 100, starting at 800. Copy and paste your distribution tables here. 5. Construct a histogram based on this frequency distribution table for the data. Copy and paste your histogram here. Describe the shape of the histogram. (Is it unimodal, bimodal, skewed, etc.?)

819

836

888

897

903

907

912

918

942

943

952

959

962

986

992

994

1004

1005

1007

1015

1016

1018

1020

1022

1034

1038

1072

1077

1077

1082

1096

1100

1113

1113

1116

1153

1154

1174

1188

1230

Answers

Answer:

Step-by-step explanation:

Hello!

You have the information about light bulbs (i believe is their lifespan in hours) And need to organize the information in a frequency table.

The first table will be with a class width of 20, starting with 800. This means that you have to organize all possible observations of X(lifespan of light bulbs) in a class interval with an amplitude of 20hs and then organize the information noting their absolute frequencies.

Example

1) [800;820) only one observation classifies for this interval x= 819, so f1: 1

2)[820; 840) only one observation classifies for this interval x= 836, so f2: 1

3)[840;860) no observations are included in this interval, so f3=0

etc... (see attachment)

[ means that the interval is closed and starts with that number

) means that the interval is open, the number is not included in it.

fi: absolute frequency

hi= fi/n: relative frequency

To graph the histogram you have to create the classmark for each interval:

x'= (Upper bond + Lower bond)/2

As you can see in the table, there are several intervals with no observed frequency, this distribution is not uniform least to say symmetric.

To check the symmetry of the distribution is it best to obtain the values of the mode, median and mean.

To see if this frequency distribution has one or more modes you have to identify the max absolute frequency and see how many intervals have it.

In this case, the maximal absolute frequency is fi=6 and only one interval has it [1000;1020)

[tex]Mo= LB + Ai (\frac{D_1}{D_1+D_2} )\\[/tex]

LB= Lower bond of the modal interval

D₁= fmax - fi of the previous interval

D₂= fmax - fi of the following interval

Ai= amplitude of the modal interval

[tex]Mo= 1000 + 20*(\frac{(6-3)}{(6-3)+(6-4)} )=1012[/tex]

This distribution is unimodal (Mo= 1012)

The Median for this frequency:

Position of the median= n/2 = 40/2= 20

The median is the 20th fi, using this information, the interval that contains the median is [1000;1020)

[tex]Me= LB + Ai*[\frac{PosMe - F_{i-1}}{f_i} ][/tex]

LB= Lower bond of the interval of the median

Ai= amplitude of the interval

F(i-1)= acumulated absolute frequency until the previous interval

fi= absolute frequency of the interval

[tex]Me= 1000+ 20*[\frac{20-16}{6} ]= 1013.33[/tex]

Mean for a frequency distribution:

[tex]X[bar]= \frac{sum x'*fi}{n}[/tex]

∑x'*fi= summatory of each class mark by the frequency of it's interval.

∑x'*fi= (810*1)+(230*1)+(870*0)+(890*2)+(910*4)+(930*0)+(950*4)+(970*1)+(990*3)+(1010*6)+(1030*4)+(1050*0)+(1070*3)+(1090*2)+(1110*4)+(1130*0)+(1150*2)+(1170*1)+(1190*1)+(1210*0)+(1230*1)= 40700

[tex]X[bar]= \frac{40700}{40} = 1017.5[/tex]

Mo= 1012 < Me= 1013.33 < X[bar]= 1017.5

Looking only at the measurements of central tendency you could wrongly conclude that the distribution is symmetrical or slightly skewed to the right since the three values are included in the same interval but not the same number.

*-*-*

Now you have to do the same but changing the class with (interval amplitude) to 100, starting at 800

Example

1) [800;900) There are 4 observations that are included in this interval: 819, 836, 888, 897 , so f1=4

2)[900;1000) There are 12 observations that are included in this interval: 903, 907, 912, 918, 942, 943, 952, 959, 962, 986, 992, 994 , so f2= 12

etc...

As you can see this distribution is more uniform, increasing the amplitude of the intervals not only decreased the number of class intervals but now we observe that there are observed frequencies for all of them.

Mode:

The largest absolute frequency is f(3)=15, so the mode interval is [1000;1100)

Using the same formula as before:

[tex]Mo= 1000 + 100*(\frac{(15-12)}{(15-12)+(15-8)} )=1030[/tex]

This distribution is unimodal.

Median:

Position of the median n/2= 40/2= 20

As before is the 20th observed frequency, this frequency is included in the interval [1000;1100)

[tex]Me= 1000+ 100*[\frac{20-16}{15} ]= 1026.67[/tex]

Mean:

∑x'*fi= (850*4)+(950*12)+(1050*15)+(1150*8)+(1250*1)= 41000

[tex]X[bar]= \frac{41000}{40} = 1025[/tex]

X[bar]= 1025 < Me= 1026.67 < Mo= 1030

The three values are included in the same interval, but seeing how the mean is less than the median and the mode, I would say this distribution is symmetrical or slightly skewed to the left.

I hope it helps!

supposee you start saving today for a $8000 down payment that you plan to make on a condo in 4 years. Assume that you make no deposits into the account after your initial deposit. The account has quarterly compounding and an APR of 6%. How much would you need to deposit now to reach your $8000 goal in 4 years

Answers

Final answer:

To reach a $8000 down payment in 4 years with an account that compounds quarterly at an APR of 6%, you would need to make an initial deposit of approximately $6304.05 today.

Explanation:

To calculate the initial deposit needed to save for a $8000 down payment in 4 years with an account that offers quarterly compounding at an APR of 6%, we use the compound interest formula:

[tex]P = A / (1 + r/n)^{(nt)[/tex]

Where:

P is the principal amount (initial deposit)A is the future value of the investment/loan, including interestr is the annual interest rate (decimal)n is the number of times that interest is compounded per yeart is the time the money is invested/borrowed for, in years

Given:

A = $8000r = 6/100 = 0.06 (as a decimal)n = 4 (quarterly compounding)t = 4 years

Now we can calculate the initial deposit:

[tex]P = $8000 / (1 + 0.06/4)^(4*4)P = $8000 / (1 + 0.015)^(16)P = $8000 / (1.015)^16P \approx $8000 / 1.26824179P \approx $6304.05[/tex]

Therefore, you would need to deposit approximately $6304.05 today to have $8000 in 4 years in the account with the given interest rate and compounding frequency.

Learn more about initial deposit here:

https://brainly.com/question/10217245

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To reach an $8000 goal in 4 years with a 6% APR compounded quarterly, you need to deposit approximately $6307.17 now.

To determine how much to deposit now to reach your $8000 goal in 4 years with quarterly compounding and an APR of 6%, you can use the formula for compound interest:

[tex]P = A / (1 + r/n)^(nt)[/tex]

Where:

P = initial deposit (what we're solving for)A = future value ($8000)r = annual interest rate (6% or 0.06)n = number of times interest is compounded per year (4 for quarterly)t = number of years (4)

Now, substitute the given values into the formula:

P = [tex]$8000 / (1 + 0.06/4)^(4*4)[/tex]

P = $8000 / [tex](1 + 0.015)^(16)[/tex]

P = $8000 / [tex](1.015)^(16)[/tex]

P = $8000 / 1.2682 (approximately)

P = $6307.17 (approximately)

So, you would need to deposit approximately $6307.17 now to reach your $8000 goal in 4 years with quarterly compounding at a 6% APR.

Patrice Patriot has dimes and uarters in a piggy bank. She has a total of 20 coins for atotal of $4.25. How many dimes does she have?

Answers

Answer:

see the picture of work shown

Answer:she has 5 dimes and 15 quarters.

Step-by-step explanation:

A dime is worth 10 cents. Converting to dollars, it becomes

10/100 = $0.1

A quarter is worth 25 cents. Converting to dollars, it becomes

25/100 = $0.25

Let x represent the number of dimes that she has.

Let y represent the the number of quarters that she has

Patrice Patriot has a total of 20 coins. It means that

x + y = 20

The total worth of dimes and quarters that she has in a piggy bank is $4.25. It means that

0.1x + 0.25y = 4.25 - - - - - - - - - -1

Substituting x = 20 - y into equation 1, it becomes

0.1(20 - y) + 0.25y = 4.25

2 - 0.1y + 0.25y = 4.25

- 0.1y + 0.25y = 4.25 - 2

0.15y = 2.25

y = 2.25/0.15

y = 15

x = 20 - y = 20 - 15

x = 5

6-27. Erin started with one corner of a figure located at (−4, 5) and translated it to end at (6, 8). To find
out how far the shape moved horizontally, she decided to find the difference between the two xcoordinates. She wrote: 6 − (−4).

Answers

Answer:

The horizontal move of the shape was 10 units to the right,

Explanation:

The problem requires that you find how far the shape was moved horizontally.

To find the horizontal translation of the shape, you must subtract the x-coordinate of the original corner (the pre-image) from the x-coordinate of the final corner (the image)

Final corner (image):

Coordinates: (6,8)x-coordinate: 6

Original corner (preimage):

Coordinate: (-4,5)x-coordinate: -4

Translation:

Difference = 6 - (-4), which is what Erin wroteSimplify: 6 + 4 = 10

Thus, the horizontal move of the shape was 10 units to the right.

2. The beam of a lighthouse can be seen for up to 20 miles. You are on a ship that is 10 miles east and 16 miles north of the lighthouse. Write an inequality to describe the region lit by the lighthouse beam. Can you see the lighthouse beam on your ship?​

Answers

Answer:

The person on the ship can see the lighthouse

Step-by-step explanation:

The Circle Function

A circle centered in the point (h,k) with a radius r can be written as the equation

[tex](x-h)^2+(y-k)^2=r^2[/tex]

Any point (x,y) can be known if it's inside of the circle if

[tex](x-h)^2+(y-k)^2\leq r^2[/tex]

The question is about a beam of a lighthouse than can be seen for up to 20 miles. If we assume the lighthouse is emitting the beam as the shape of a circle centered in (0,0), then its radius is 20 miles. Thus any person riding a ship inside the circle can see the lighthouse. This means that

[tex]x^2+y^2\leq 20^2[/tex]

[tex]x^2+y^2\leq 400[/tex]

The ship's coordinates respect to the lighthouse are (10,16). We should test the point to verify if the above inequality stands

[tex]10^2+16^2\leq 400[/tex]

[tex]356 \leq 400[/tex]

The inequality is true, so the person on the ship can see the lighthouse

The inequality is:

√(x^2 + y^2) ≤ 20 mi.

And you can see the lighthouse beam from your ship.

How to write the inequality?

First, let's define our coordinate system, North will be the positive y-axis and east will be the positive x-axis. Such that the origin is the lighthouse.

The distance between a point (x, y) and the lighthouse is given by:

d = √(x^2 + y^2).

And we know that the lighthouse beam can be seen for up to 20 miles, so you can only see the lighthouse if your position (x, y) is such that the inequality is true.

√(x^2 + y^2) ≤ 20 mi.

Now, can you see the lighthouse beam from your ship?

Your ship's position is: (10 mi, 16 mi)

Replacing that in the inequality we get:

√((10mi)^2 + (16mi)^2) ≤ 20 mi

18.87 mi ≤ 20 mi

The inequality is true, then you can see the beam from the ship.

If you want to learn more about inequality, you can read:

https://brainly.com/question/25275758

what is the slope intercept equation of the line that goes through the points (1,-5) and (-3,7)?​

Answers

Answer:

y=-3x-2

Step-by-step explanation:

The slope intercept equation is y=mx+b. y2-y1/x2-x1 is the equation for the slope. 7-(-5)/-3-1 is -3. Now you have y=-3x+b, you plug in one set of cordinates so you would have 7=-3(-3)+b, 7=9+b, b=-2

y=-3x-2

Hope that helps :)

Answer:

Step-by-step explanation:

The equation of a straight line can be represented in the slope-intercept form, y = mx + c

Where c = intercept

Slope, m =change in value of y on the vertical axis / change in value of x on the horizontal axis

change in the value of y = y2 - y1

Change in value of x = x2 -x1

y2 = final value of y

y 1 = initial value of y

x2 = final value of x

x1 = initial value of x

The line passes through the points (1,-5) and (-3,7)

y2 = 7

y1 = - 5

x2 = - 3

x1 = 1

Slope,m = (7 - - 5)/(- 3 - 1) = 12/- 4 =

- 3

To determine the intercept, we would substitute x = - 3, y = 7 and m= - 3,

7 = - 3 × - 3 + c = 9 + c

c = 7 - 9 = - 2

The equation becomes

y = - 3x - 2

f(x)={5−1 if 1≤x<7, if 7≤x≤13. Evaluate the definite integral by interpreting it as signed area.

Answers

Answer:

\int\limits^7_1 {f(x)} \, dx =24

\int\limits^13_7 {f(x)} \, dx =24

Step-by-step explanation:

From Exercise we have f(x)=5-1 , we get f(x)=4.

We calculate integral, if 1≤x<7, we get

\int\limits^7_1 {f(x)} \, dx =\int\limits^7_1 {4} \, dx =4[x]\limits^7_1=4(7-1)=4·6=24

We calculate integral, if 7≤x<13, we get

\int\limits^13_7 {f(x)} \, dx =\int\limits^13_7 {4} \, dx =4[x]\limits^13_7=

=4(13-7)=4·6=24

Therefore, we conclude that the given two integrals are the same.

You randomly select 500 students and observe that 85 of them smoke. What is your estimate of the probability that a randomly selected student smokes?

Answers

Answer:

17% probability that a randomly selected student smokes.

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

What is your estimate of the probability that a randomly selected student smokes?

This estiamte is the number of smoking students divided by the total number of students.

We have that:

There are 500 students.

85 smoke

So there is an 85/500 = 0.17 = 17% probability that a randomly selected student smokes.

If an annuity makes an infinite series of equal payments at the end of the interest periods, it is called a perpetuity. If a lump sum investment of An is needed to result in n periodic payments of R when the interest rate per period is i, then the sum is represented by the following.
An = R 1 - (1 + i)^-n
i


Evaluate the following limit to find a formula for the lump sum payment for a perpetuity.

lim An
n?

Answers

Answer:

[tex]lim_{n \to \infty} A_n = \frac{R}{i}[/tex]

Step-by-step explanation:

For this case we have this expression:

[tex] A_n = R [\frac{1 -(1+i)^{-n}}{i}][/tex]

The lump sum investment of An is needed to result in n periodic payments of R when the interest rate per period is i.

And we want to find the:

[tex] lim_{n \to \infty} A_n[/tex]

So we have this:

[tex] lim_{n \to \infty} A_n = lim_{n \to \infty}R [\frac{1 -(1+i)^{-n}}{i}] [/tex]

Then we can do this:

[tex] lim_{n \to \infty} A_n = lim_{n \to \infty} R [\frac{1 -\frac{1}{(1+i)^n}}{i}][/tex]

[tex]lim_{n \to \infty} A_n = R lim_{n \to \infty} [\frac{1 -\frac{1}{(1+i)^n}}{i}][/tex]

And after find the limit we got:

[tex] lim_{n \to \infty} A_n = R [\frac{1-0}{i}][/tex]

Becuase : [tex] \frac{1}{(1+i)^{\infty}} =0[/tex]

And then finally we have this:

[tex]lim_{n \to \infty} A_n = \frac{R}{i}[/tex]

Find, correct to the nearest degree, the three angles of the triangle with the given vertices.

A(1, 0, −1), B(5, −3, 0), C(1, 5, 2)

∠CAB =

∠ABC =
∠BCA =

Answers

Answer:

angle CAB = 113.8 degree

angle ABC = 35.6 degree

angle BCA = 30.6 degree

Step-by-step explanation:

Given data:

A(1, 0, −1),

B(5, −3, 0),

C(1, 5, 2)

calculate the length of side by using the distance formula

so

AB = (5,-3,0) - (1,0,-1) = (4,-3,1)

AC= (1,5,2) - (1,0,-1) = (0,5,3)

|AB|

|AC| =[tex]\sqrt {(0 + 5^2+3^2)} = \sqrt{34}[/tex]

From following formula, calculate the angle between the two side i.e Ab and AC

AB.AC = |AB|*|AC| cos ∠CAB

(4,-3,1).(0,5,3)

4*0 -3*5 +1*3

-12 =

cos ∠CAB = - 0.404

angle CAB = 113.8 degree

BA =B- A =  (1,0,-1) - (5,-3,0) = (-4,3,-1)

BC = (1,5,2)-(5,-3,0) = (-4,8,2)

|BA| = \sqrt{(26)}

|BC| [tex]= \sqrt {(4^2 + 8^2 + 2^2)} = \sqrt{(84)}[/tex]

BA.BC = |BA|*|BC|* cosABC

(-4,3,-1).(-4,8,2) =[tex]\sqrt{(26)} * \sqrt{(84)} *cosABC[/tex]

16+24-2

cos ∠ABC = 0.813

angle ABC = 35.6 degree

we know sum of three angle in a traingle is 180 degree hence

sum of all three angle = 180

angle BCA + 35.6 + 113.8 = 180

angle BCA = 30.6 degree

Find all values of x in the interval [0, 2π] that satisfy the equation.

6sin²(x) = 3

Answers

Answer:

The solutions are π/4, 3π/4,5π/4,7π/4

Step-by-step explanation:

The given equation is

6sin²(x) = 3

Divide by 6 to get:

[tex] { \sin}^{2} (x) = \frac{1}{2} [/tex]

This implies that;

[tex] \sin(x) = \pm \frac{ \sqrt{2} }{2} [/tex]

If

[tex]\sin(x) = \frac{ \sqrt{2} }{2}[/tex]

[tex]x = \frac{\pi}{4} [/tex]

in the first quadrant

[tex]x = \frac{3\pi}{4} [/tex]

in the second quadrant.

If

[tex]\sin(x) = - \frac{ \sqrt{2} }{2}[/tex]

[tex]x = \frac{5\pi}{4} [/tex]

in the third quadrant

[tex]x = \frac{7\pi}{4} [/tex]

Suppose that the number of gallons of milk sold per day at a local supermarket are normally distributed with mean and standard deviation of 436.6 and 23.23, respectively. What is the probability that on a given day the supermarket will sell below 449 gallons of milk?

Answers

Answer:

70.19% probability that on a given day the supermarket will sell below 449 gallons of milk.

Step-by-step explanation:

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.

In this problem, we have that:

[tex]\mu = 436.6, \sigma = 23.23[/tex]

What is the probability that on a given day the supermarket will sell below 449 gallons of milk?

This is the pvalue of Z when X = 449. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{449 - 436.6}{23.23}[/tex]

[tex]Z = 0.53[/tex]

[tex]Z = 0.53[/tex] has a pvalue of 0.7019.

So there is a 70.19% probability that on a given day the supermarket will sell below 449 gallons of milk.

It takes you 47 seconds to walk from the first​ (ground) floor of a building to the third floor.
How long will it take you to walk from the first floor to the sixth floor​ (at the same​ pace, assuming all floors have the same​ height)?

Answers

Answer: 117.5 seconds

Step-by-step explanation:

Given : It takes you 47 seconds to walk from the first​ (ground) floor of a building to the third floor.

Since from first floor to third , a person need to pass two levels of staircase.

We assume that the person walk at the same​ pace and the height of all floors are same.

The time taken to pass each level = (Time taken to pass 2 levels) ÷ 2

= (47 seconds)  ÷ (2) = 23.5 seconds

Also, the from first floor to sixth floor , a person need to pass 5 levels of staircase.

Then, the time taken to pass each level = 5 x (Time taken to pass one level)

= 5 x 23.5 =117.5 seconds

Hence, it will take 117.5 seconds to walk from the first floor to the sixth floor.

Find the inverse of the function âf(x)equals 18x .Verify that f (f Superscript negative 1 Baseline (x ))equalsxand f Superscript negative 1 Baseline (f (x ))equalsx.f Superscript negative 1 Baseline (x )equalsnothing

Answers

Answer:

inverse f-1 (x) = x/18

Step-by-step explanation:

To find the inverse of a function f-1 (x), we represent f(x) by y or let f(x) = y

then make x the subject of the formula,

f(x) = 18x

Let f(x) = y

hence Y = 18x, make x the subject of the formula, do that by dividing both sides by 18,

Y/18 = x or x = Y/18

Interchanging or swapping x and y, therefore f-1 (x) = x/18

therefore, F(x) = 18x, the inverse f-1 (x) = x/18

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