Two Population Means with Unknown Standard Deviations · Exercise 21

The U.S. Center for Disease Control reports that the mean life expectancy was 47.6 years for White people born in 1900 and 33.0 years for non-White people. Suppose that you randomly survey death records for people born in 1900 in a certain county. Of the 124 White people, the mean life span was 45.3 years with a standard deviation of 12.7 years. Of the 82 non-White people, the mean life span was 34.1 years with a standard deviation of 15.6 years. Conduct a hypothesis test to see if the mean life spans in the county were the same for White and non-White people.

Is this a right-tailed, left-tailed, or two-tailed test?

OpenStax, Introductory Statistics 2e · §10.1 Two Population Means with Unknown Standard Deviations · Exercise 21