Question

1. the data collected from the 2012 General Social Survey (GSS) in which 1,298 respondents reported on the number of hours they watched tv per day. The results show that the average (mean) number of hours spent watching tv per day is 3.089 hours with a standard deviation of .07 hours.

a. Calculate 95% confidence interval to estimate the mean number of hours of tv the average American watches per day based on these data.

b. What do you notice about the relationship between the sample standard deviation and the precision of the estimate?

Answer 1

(A) Given that :- mean = 3.089, population standard deviation = 0.07 and sample size is n = 1298

sample size is large enough to assume that the sample standard deviation is equal to population standard deviation

z score for 95% confidence interval is 1.96 (using z distribution table)

confidence interval =

(B) There is a inverse relationship between the sample standard deviation and the precision of the estimate because as the sample stadard deviation increases, the precision of estimate decreases or vice versa.