Bob scored 85 on a math exam and the mean was 77 and standard deviation was 6. Tricia scored 78 where the mean was 73 and standard deviation was 4. Shirley scored 92 on the English exam where the mean was 86 and the standard deviation was 5. Compare the scores and rank them from best to worst.

Take the first one. (85-77)/6=4/3

This means Bob scored 1.33 standard deviations above the mean.

Also, if we look up 4/3 in the z-table we see we get .9088

That means that Bob scored higher than 90% of those who took the test.

Compare the other two.