1. In the 1982 General Social Survey. 350 subjects reported the time spent every day watch- ing television. The sample mean was 4 1 hours, with standard deviation 3.3. In the 1994 General Social Survey, 1965 subjects reported a mean time spent watching television of 2.8 hours, with standard deviation 2.0.

a) Construct the 95% confidence interval for the difference between the means in 1982 and 1994 Interpret. Is it plausible that the mean was the same in both years?

b) Set up the hypotheses of a significance test to analyze whether the population means differ in 1982 and 1994.

c) For this test, construct the test statistic. Report and interpret the P-value.

d) Do you thank the distribution of the response variable is approximately normal? Why? Does this affect the validity of your inference? Explain.