A student computed a 95% confidence interval for the mean, , of a population as (13, 20). Based on this interval,

a. the method gives correct results 95% of the time.

b. there is a 95% chance is in the interval.

c. 95% of the observations lie in the interval.

You wish to find a 95% confidence interval for the mean number of times men change channels with a remote control during a commercial. Based on a preliminary study, you estimate = 15. How many commercials' worth of data do you need to have a margin of error no more than 3?

a.10

b.97

c. 96

What is theP-value for a test of the hypothesesH₀: = 10 againstH_a: 10 if the calculated statistic isz= 2.56?

a. 0.0104

b. 0.9948

c. 0.0052