A Student Doing a History Project Finds the Ages of All

Multiple Choice

A student doing a history project finds the ages of all of the governors of California at the time they were first elected and the ages of all the governors of Massachusetts at the time they were first elected, and then computes the mean for each state. The best way to determine if there is a difference in the mean age for the past governors of the two states is to

A) compute a 95% confidence interval for the difference.
B) compute a confidence interval for each mean and see if they overlap.
C) test the hypothesis that the means are the same versus that they are different.
D) subtract the two computed means and see whether the difference is 0.