Given information
Use the following information to answer the next exercises: The U.S. Center for Disease Control reports that the mean life expectancy was years for whites born in and years for nonwhites. Suppose that you randomly survey death records for people born in in a certain county. Of the whites, the mean life span was years with a standard deviation of years. Of the nonwhites, the mean life span was years with a standard deviation of years. Conduct a hypothesis test to see if the mean life spans in the county were the same for whites and nonwhites.
Step-by-step explanation
The random variable of interest in the given hypothesis test in symbols is as follows:
If the mean life span of whites is , and the mean life span of nonwhites is .
Then,
is the required random variable for the problem.