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 15 and 52 minutes. Suppose that the population mean timecustomersspent onthatwebsite is 12 minutes a day. Does this value of the population mean help to show that the confidence interval estimate is correct? Explain.

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

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

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

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

E. Yes,becausethepopulationmean,,isrelativelycloseto 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).

b. On the basis of these results, do you think that the distributor has a right to complain to the water bottling company? Why?

Yes / No, because a 1-gallon bottle containing exactly 1-gallon of water lies within / outside the 99%

confidence interval.

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.)

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.

b. Construct a 95% confidence interval estimate for the population proportion of travelers who said that reputation was very important in choosing an airline.

enter your response here enter your response here

(Round to four decimal places as needed.)

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) and (b) below.

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

enter your response here enter 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% 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

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.

A. True

B. 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.

D. Yes. This proportion is within the limits of the confidence interval.

23. A team of researchers analyzed the meat from each in a sample of 19 "red snapper" fish fillets purchased from vendors across a region in an effort to estimate the true proportion of fillets that are really red snapper. DNA tests revealed that 16 of the 19 fillets (or 84%) were not red snapper but a cheaper look-alike variety of fish. Complete parts a through c.

a.The parameter "" is the true proportion of fish fillets that are actually red snapper.

A. True

B. False

b. Explain why it is not appropriate to use a confidence interval in this study. Choose the correct answer below.

A. It is inappropriate because the sampling distribution is approximately normal.

B. It is inappropriate because either the number of successes in the sample or the number of failures in the sample is greater than or equal to 5.

C. It is inappropriate because the expected probability of success is 0.84.

D. It is inappropriate because either the number of successes in the sample or the number of failures in the sample is less than 5.

c. The population (true) proportion of fish fillets that are actually red snapper isenter your response here.

(Use 2 decimal places rounded.)

24. Find the indicated Z score ( or Z-value). The graph depicts the standard normal distribution with mean 0 and standard deviation 1.*Note- Z score (or Z-value) is also known as Z critical value.

z 0.1335 0

(Round to two decimal places as needed in ALL questions.)

[b] If the shaded area has value .025, then the Z-value must be enter your response here

[c] If the shaded area has value .005, then the Z-value must be enter your response here

[d] If the shaded area has value .115, then the Z-value must be enter your response here