Question

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 34 death-row inmates and finds that their mean age is 38.5, with a standard deviation of 10.2.  Does this data indicate that the mean age of death-row inmates has changed significantly since 2002. Use the α = 0.05 level of significance.

On a separate sheet of paper, write down the hypotheses (H₀ and H_a) to be tested.

Conditions:
We [a] (are / are not) able to determine if the data is normally distributed from the given description.
The t-test for means [b] (is / is not) valid for the given data.

Rejection Region:
To test the given hypotheses, we will use a (left / right / two) [c]-tailed test. The appropriate critical value(s) for this test is/are [d].  (Report your answer exactly as it appears in Table VI. For two-tailed tests, report both critical values in the answer blank separated by only a single space.)

Refer to the data and Minitab Express output from Question 1.

The test statistic for this test is t₀=[a].  (Calculate this value in a single step in your calculator, and report your answer rounded to 3 decimal places.)

Label the test statistic in your sketch from Question 1. Use this sketch to conclude the hypothesis test.

We [b] (reject / fail to reject) H₀.
The given data [c] (does / does not) provide significant evidence that the age of death-row inmates has changed since 2002.

Answer 1