17.

[-/6 Points]DETAILSASWSBE14 8.TB.2.045.

MY NOTES

ASK YOUR TEACHER

PRACTICE ANOTHER

You may need to use the appropriateappendix tableortechnologyto answer this question.

You are given the following information obtained from a random sample of 6 observations. Assume the population has a normal distribution.

• 15
• 23
• 22
• 19
• 21
• 20

(a)

What is the point estimate of?

(b)

Construct an 80% confidence interval for. (Round your answers to three decimal places.)

to

(c)

Construct a 98% confidence interval for. (Round your answers to three decimal places.)

to

(d)

Discuss why the 80% and 98% confidence intervals are different.

As the sample size increases and all else stays the same, the confidence interval becomes narrower.As the confidence level increases and all else stays the same, the confidence interval becomes narrower. As the confidence level increases and all else stays the same, the confidence interval becomes wider.As the sample size increases and all else stays the same, the confidence interval becomes wider.Changing the confidence level or sample size while all else stays the same shifts the confidence interval left or right.

18.

[-/4 Points]DETAILSASWSBE14 8.TB.2.050.

MY NOTES

ASK YOUR TEACHER

PRACTICE ANOTHER

You may need to use the appropriateappendix tableortechnologyto answer this question.

In order to determine how many hours per week freshmen college students watch television, a random sample of256 studentswas selected. It was determined that the students in the sample spent an average of16hourswith a standard deviation of3.8hourswatching TV per week. (Round your answers to three decimal places.)

(a)

Provide a 95% confidence interval estimate for the average number of hours that all college freshmen spend watching TV per week.

hours to hours

(b)

Assume that a sample of64students was selected that resulted in the same mean and standard deviation. Provide a 95% confidence interval estimate for the average number of hours that all college freshmen spend watching TV per week.

hours to hours