2) If X=85, =11, and n=69, construct a 99% confidence interval estimate of the population mean, .

enter your response here enter your response here

(Round to two decimal places as needed.)

3) A market researcher collects a simple random sample of customers from a population of over a million customersthat use a home improvement website. After analyzing the sample, she states that she has 95% confidence that the mean timecustomersspent on thatwebsite per day is between 16 and 59 minutes. Suppose that the population mean timecustomersspent onthatwebsite is 48 minutes a day. Does this value of the population mean help to show that the confidence interval estimate is correct? Explain.

Choose the correct answer below.

A. Yes, because the population mean, is within 95% of the midpoint of the confidence interval estimate.

B. No, because the population mean, , isnot included within the confidence interval estimate.

C. Yes, because the population mean, , is included within the confidence interval estimate.

D. No,becausethepopulationmean,,isnotinthemiddlehalfof the confidence interval estimate.

E. No, because the population mean, , is not the midpoint of the confidence interval estimate.

5) A bottled water distributor wants to estimate the amount of water contained in 1-gallon bottles purchased from a nationally known water bottling company. The water bottling company's specifications state that the standard deviation of the amount of water is equal to 0.03 gallon. A random sample of 50 bottles is selected, and the sample mean amount of water per 1-gallon bottle is 0.963 gallon. Complete parts (a) through (d).

a. Construct a 99% confidence interval estimate for the population mean amount of water included in a 1-gallon bottle.

enter your response here enter your response here

(Round to five decimal places as needed.)

6) If X=99, S=14, and n=36, and assuming that the population is normally distributed, construct a 99% confidence interval estimate of the population mean, .

enter your response here enter your response here

(Round to two decimal places as needed.)

8) A survey of nonprofit organizations showed that online fundraising has increased in the past year. Based on a random sample of 50 nonprofits, the mean one-time gift donation in the past year was $38, with a standard deviation of $7.

Complete parts a and b below.

a. Construct a 95% confidence interval estimate for the population one-time gift donation.

3636 4040

(Type integers or decimals rounded to two decimal places as needed.)

I need an asnwer for part 2:)

Part 2

b. Interpret the interval constructed in (a).

Choose the correct answer below.

A. The quality improvement team can be 95%

confident that the new population mean turnaround time is the midpoint of the confidence interval.

B. The quality improvement team can be completely sure that the new population mean turnaround time is contained within the confidence interval.

C. The quality improvement team can be completely sure that the new population mean turnaround time is the midpoint of the confidence interval.

D. The quality improvement team can be 95% confident that the new population mean turnaround time is contained within the confidence interval.

9). The table below contains the amount that a sample of nine customers spent for lunch ($) at a fast-food restaurant. Complete parts a and b below.

4.11

5.12

5.67

6.55

7.26

7.89

8.12

8.62

9.51

a. Construct a 99% confidence interval estimate for the population mean amount spent for lunch at a fast-food restaurant, assuming a normal distribution.

The % confidence interval estimate is from $enter your response here to $enter your response here.

(Round to two decimal places as needed.)

11) In a survey of 3,907 travelers, 1,474 said that location was very important for choosing a hotel and 1,214

said that reputation was very important in choosing an airline. Complete parts (a) through (c) below.

a. Construct a 95% confidence interval estimate for the population proportion of travelers who said that location was very important for choosing a hotel.

enter your response hereenter your response here

(Round to four decimal places as needed.)

17) Determine the upper-tail critical value t(/2) in each of the following circumstances.

a.	1=0.99,n=50		d.	1=0.99,n=27
b.	1=0.95,n=50		e.	1=0.90,n=40
c.	1=0.99,n=66

a. t=enter your response here

(Round to four decimal places as needed.)

b. t=enter your response here

(Round to four decimal places as needed.)

c. t=enter your response here

(Round to four decimal places as needed.)

d. t=enter your response here

(Round to four decimal places as needed.)

e. t=enter your response here

(Round to four decimal places as needed.)

18) Assuming that the population is normally distributed, construct a

99% confidence interval for the population mean, based on the following sample size of n=8.

1, 2, 3, 4,5,6,7, and 22 Change the number 22 to 8 and recalculate the confidence interval. Using these results, describe the effect of an outlier (that is, an extreme value) on the confidence interval.

Find a 99% confidence interval for the population mean, using the formula or calculator.

enter your response hereenter your response here

(Round to two decimal places as needed.)

Change the number 22 to 8. Find a 99% confidence interval for the population mean, using the formula or

calculator.

enter your response hereenter your response here

(Round to two decimal places as needed.)

What is the effect of an outlier on the confidence interval?

A. The presence of an outlier in the original data increases the value of the sample mean and greatly decreases the sample standard deviation, narrowing the confidence interval.

B. The presence of an outlier in the original data decreases the value of the sample mean and greatly inflates the sample standard deviation, widening the confidence interval.

C. The presence of an outlier in the original data decreases the value of the sample mean and greatly decreases the sample standard deviation, narrowing the confidence interval.

D. The presence of an outlier in the original data increases the value of the sample mean and greatly inflates the sample standard deviation, widening the confidence interval.

19)The data below represents the overall miles per gallon (MPG) of 2008 SUVs priced under $30,000. Complete parts a and b below.

22,21,20,23,17,17,15,16,20,19,19, 16,22,18,18,17,18,18,15,21,18,24

a. Construct a 90% confidence interval estimate for the population mean miles per gallon of 2008 SUVs priced under $30,000, assuming a normal distribution.

enter your response hereenter your response here

(Round to two decimal places as needed.)

b.Interpret the interval constructed in (a). Choose the correct answer below.

A. With 90% confidence, the mean miles per gallon in the sample of 2008 SUVs is somewhere in the interval.

B. With 90% confidence, the mean miles per gallon in the sample of 2008 SUVs is the population mean.

C. With 90% confidence, the mean miles per gallon in the population of 2008 SUVs is the sample mean.

D. With 90% confidence, the mean miles per gallon in the population of 2008 SUVs is somewhere in the interval.

20) 19A telecommunications company wants to estimate the proportion of households that would purchase an additional telephone line if it were made available at a substantially reduced installation cost. Data are collected from a random sample of 500 households. The results indicate that 110 of the households would purchase the additional telephone line at a reduced installation cost. Complete parts (

-a.Construct a 95% confidence interval estimate for the population proportion of households that would purchase the additional telephone line.

enter your response hereenter your response here

(Round to four decimal places as needed.)

b.The margin of error

e=enter your response here

(Round to 3 decimal places as needed.)

c.The critical value for the upper tail is

enter your response here

(Round to 2 decimal places as needed.)

d. How would the manager in charge of promotional programs concerning residential customers use the results in (a)?

A. The manager can infer with 95% confidence that the population proportion of all households that would purchase an additional telephone line is somewhere in this interval.

B. The manager can infer with 95% confidence that the proportion of households in the sample that would purchase an additional telephone line is somewhere in this interval.

C. The manager can infer that the true population proportion of households that would purchase an additional telephone line is somewhere in this interval 95% of the time.

D. The manager can infer that 95% of households would purchase an additional telephone line.

21) In 2010, a survey of 2500 homes in a region found that 500 had overestimated market values. Suppose you want to estimate "", the population proportion of homes in this region with market values that are overestimated.

a. Find p, the point estimate of .

b. Describe the distribution used to find the critical value.

c. Find a 95% confidence interval for .

d. Give a practical interpretation of the confidence interval from part c.

e. Suppose a researcher claims that =0.13.

Is the claim believable? Explain.

a. The point estimate is enter your response here.

(Type an integer or a decimal.)

b. We use the t-distribution to find the critical value for the confidence interval of a proportiuion.

True

False

c. The 95% confidence interval is (enter your response here,enter your response here).

(Round to two decimal places as needed.)

d. Interpret the confidence interval.

One can be enter your response here% confident that the interval contains the true value of the population proportion

e. Is the claim that =0.13 believable?

A. No. This proportion is below the lower limit of the confidence interval.

B. No. This proportion is beyond three standard deviations of the sample mean.

C. Yes. This proportion is within three standard deviations of the sample mean.

22) Suppose data collected by observers at randomly selected intersections across the country revealed that in a sample of 100 drivers, 50 were using their cell phone.

a. Give a point estimate of , the true driver cell phone use rate (that is, the true proportion- or- population porportion- of drivers who are using their cell phone while driving).

b. Compute a 99% confidence interval for .

c. Give a practical interpretation of the interval, part b.

a. A point estimate for is enter your response here.

b. The 99% confidence interval for the population proportion is (enter your response here,enter your response here).

(Round to two decimal places as needed.)

c. Interpret this interval.

A. We are confident that 99% of the population use a cell phone while driving.

B. There is a 99% percent chance that the population proportion of drivers who use cell phones is outside this interval.

C. We are 99% confident that the population proportion of drivers using cell phones is inside this interval.

D. We are confident that 99% of the population do not use a cell phone while driving.

27) A political pollster is conducting an analysis of sample results in order to make predictions on election night. Assuming a two-candidate election, if a specific candidate receives at least 53% of the vote in the sample, that candidate will be forecast as the winner of the election. You select a random sample of

100 voters. Complete parts (a) through (c) below.

Just need b for 27

a.	What is the probability that a candidate will be forecast as the winner when the population percentage of her vote is 50.1%?

The probability is 0.28100 that a candidate will be forecast as the winner when the population percentage of her vote is 50.1%.

(Round to four decimal places as needed.)

Part 2 (i just neeed b)

b.	What is the probability that a candidate will be forecast as the winner when the population percentage of her vote is 60%?

The probability is enter your response here that a candidate will be forecast as the winner when the population percentage of her vote is 60%.

(Round to four decimal places as needed.)

just need b for 26

26) The following data represent the responses (Y for yes and N for no) from a sample of 20 college students to the question "Do you currently own shares in any stocks?"

YNNYYNYYYYYYNYYNNNNN

a. Determine the sample proportion, p, of college students who own shares of stock.

b. If the population proportion is 0.40, determine the standard error of the proportion.

a. p=0.550.55

(Round to two decimal places as needed.)

Part 2 (i just neeed b)

b. p=enter your response here

(Round to four decimal places as needed.)

Just need e for 29

29) The average salary for a certain profession is $99,000. Assume that the standard deviation of such salaries is $38,500. Consider a random sample of 77 people in this profession and let x

represent the mean salary for the sample.

a.	What is x?

x=99,000

Part 2

b.	What is x?

x=4387.48

(Round to two decimal places as needed.)

Part 3

c.	Describe the shape of the sampling distribution of x.

A. The shape is that of a binomial distribution.

B. The shape is that of a normal distribution.

Your answer is correct.

C. The shape is that of a poisson distribution.

D. The shape is that of a uniform distribution.

Part 4

d.	Find the z-score for the value x=91,000.

z=negative 1.82

(Round to two decimal places as needed.)

Part 5

e.	Find P( x>91,000.)

P( x>91,000) = enter your response here

(Round to three decimal places as needed.)

Just need e for 28 pls

28) A random sample of n=81 observations is drawn from a population with a mean equal to 20 and a standard deviation equal to 9. Complete parts a through g below.

a. Give the mean and standard deviation of the (repeated) sampling distribution x.

x=2020

x=11

Part 2

b. Describe the shape of the sampling distribution of x.

Does this answer depend on the sample size? Choose the correct answer below.

A. The shape is that of a normal distribution and does not depend on the sample size.

B. The shape is that of a uniform distribution and does not depend on the sample size.

C. The shape is that of a normal distribution and depends on the sample size.

D. The shape is that of a uniform distribution and depends on the sample size.

Part 3

c. Calculate the standard normal z-score corresponding to a value of

x=19.6.

z=negative 0.4

(Type an integer or a decimal.)

Part 4

d. Calculate the standard normal z-score corresponding to a value of x=21.5.

z=1.51.5 (Type an integer or a decimal.)

Part 5

Just need E

e. Find P (x<19.6)

Px<19.6=enter your response here

(Round to four decimal places as needed.)