According to the American Time Use Survey, adult Americans spent 42.6 minutes per day on phone calls and answering or writing email in 2006.
(a) Suppose that we want to judge whether the amount of daily time spent on phone calls and answering or writing email has increased. Write the appropriate null and alternative hypothesis.
(b) The sample data indicated that the null hypothesis should be rejected. Write a conclusion.
(c) Explain what it would mean if we made a Type I error in conducting the test from part (a).
(d) Explain what it would mean if we made a Type II error in conducting the test from part (a).