A number of years ago, the road and highway maintenance department of Sin City, Nevada, began recruiting minority group members through an affirmative action program. In terms of efficiency ratings, as compiled by their superiors, how do the affirmative action employees rate? The ratings of random samples of both groups were collected, and the results are reported here (higher ratings indicate greater efficiency).
234 PART II INFERENTIAL STATISTICS Sample 1 Sample 2 (Affirmative Action) (Regular) 15.2 15.5 s1  3.9 s2 2.0 N1 97 N2 100 X2 X1 Write a sentence or two of interpretation.