n 2002 the mean age of an inmate on death row was 407 years

n 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. is there enough evidence to conclude a change in mean age of death row inmates? Use a a=.01 level of significance

Solution