Question 1.) A study was conducted to estimate , the mean number of weekly hours

Question

Question 1.) A study was conducted to estimate , the mean number of weekly hours that U.S. adults use computers at home.Suppose a random sample of 81 U.S. adults gives a mean weekly computer usage time of 8.5 hours and that from prior studies, the population standard deviation is assumed to be = 3.6 hours.

A similar study conducted a year earlier estimated that , the mean number of weekly hours that U.S. adults use computers at home, was 8 hours. We would like to test (at the usual significance level of 5%) whether the current study provides significant evidence that this mean has changed since the previous year.

Using a 95% confidence interval of (7.7, 9.3), which of the following is an appropriate conclusion?

A. The current study does provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls outside the confidence interval.

B. The current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls outside the confidence interval.

C. The current study does provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.

D. The current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.

E. You cannot draw a conclusion because the only way to reach a conclusion is to find the p-value of the test.

Explanation / Answer

The answer is "d"

7.7 < 8 < 9.3

The current study does not provide significant evidence that the mean number of weekly hours has changed over the past year, since 8 falls inside the confidence interval.

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.