Question

According to Nielsen Media Research, the average number of hours of TV viewing per household per week in the United States is 50.4 hours.
1 (a) Suppose the population standard deviation is 11.8 hours and a random sample of 42 U.S. household is taken, what is the probability that the sample mean TV viewing time is between 47.5 and 52 hours?
1 (b) Suppose the population mean and sample size is still 50.4 hours and 42, respectively, but the population standard deviation is unknown. If 72% of all sample means are greater than 49 hours, what is the value of the unknown population standard deviation?
1(c) What is the result of part (a) if the sample only consists of 5 households? Explain.


The average age of online consumers ten years ago was 23.3 years. As older individuals gain confidence with the Internet, it is believed that the average age has increased. We would like to test this belief.
2(a) Write the appropriate hypotheses to be tested.
2(b) The online shoppers in our sample consisted of 40 individuals, had an average age of 24.2 years, with a standard deviation of 5.3 years. What is the test statistic and p‐value for the hypotheses being tested in part (a)? (Remark: Report the p‐value using the statistical table, but NOT Excel function.) 2 (c) What is the practical implication of the conclusion of the hypothesis test at i. 5% level of significance, and ii. 10% level of significance?

Answer 1