# Question: A researcher wanted to determine the mean number of hours

A researcher wanted to determine the mean number of hours per week (Sunday through Saturday) the typical person watches television. Results from the Sullivan Statistics Survey indicate that s = 7.5 hours.

(a) How many people are needed to estimate the number of hours people watch television per week within 2 hours with 95% conﬁdence?

(b) How many people are needed to estimate the number of hours people watch television per week within 1 hour with 95% conﬁdence?

(c) What effect does doubling the required accuracy have on the sample size?

(d) How many people are needed to estimate the number of hours people watch television per week within 2 hours with 90% conﬁdence? Compare this result to part (a). How does

decreasing the level of conﬁdence in the estimate affect sample size? Why is this reasonable?

(a) How many people are needed to estimate the number of hours people watch television per week within 2 hours with 95% conﬁdence?

(b) How many people are needed to estimate the number of hours people watch television per week within 1 hour with 95% conﬁdence?

(c) What effect does doubling the required accuracy have on the sample size?

(d) How many people are needed to estimate the number of hours people watch television per week within 2 hours with 90% conﬁdence? Compare this result to part (a). How does

decreasing the level of conﬁdence in the estimate affect sample size? Why is this reasonable?

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