Answers for #7

7. In 2002, the mean age of an inmate on death row was 40.7 years, according to data obtained from the U.S. Department of Justice. A sociologist wondered whether the mean age of a death row inmate has changed since then. She randomly selects 32 death row inmates and finds that their mean age is 38.9 with a standard deviation of 9.6. At a significance level of 0.10, is there evidence that the mean age has changed since then? Use the p-value method. a) State HO, Ha. b) State the test you will use. (z-test, t-test, 1-prop-Ztest, etc) c) Calculate your p-value. e) State your decision. f) Interpret your decision in terms of the original