:2. The scores on a final exam follow the normal curve with an
average of 60 and an SD of 20.  The instructor wishes to count
the top 20% of the scores as A's, with the rest of the scores as
B or lower.  Which of the following final scores is the most
suitable cutoff between the A's and the B's?

 a.  55

 b.  75

 c.  65

 d.  95

 e.  85