ar, the mean age of an inmate on death row was 39.9 years. A sociologist wond the mean age of a death-row inmate has changed since then. She randomly s w inmates and finds that their mean age is 38.2, with a standard deviation of 8 ct a 95% confidence interval about the mean age. What does the interval imply k the icon to view the table of critical t-values. ince the mean age from the earlier year is not contained in the interval, there is ufficient evidence to conclude that the mean age had changed. ince the mean age from the earlier year is not contained in the interval, there is ufficient evidence to conclude that the mean age had changed. nce the mean age from the earlier year is contained in the interval, there is not fficient evidence to conclude that the mean age had changed. nce the mean age from the earlier year is contained in the interval, there is suf dence to conclude that the mean age had changed.