John and Sam sat for two different examinations. Suppose John’s grade was 75 and the average and the standard deviation of his examination were 60 and 10, respectively. Similarly, assume that Sam’s grade was 85 and the average and the standard deviation of his examination were 90 and 0.5, respectively.

a. Whose grade is better?

b. Calculate z-scores for both John’s and Sam’s grades?

c. Interpret both z-scores.

d. What do you think about their grades now?