Determine the number of standard deviations that needs to be subtracted from or added to the mean in order to arrive to the values given.
(1) 45 = 61.2 - 21.4n ; n = 0.757 (2) 78 = 61.2 + 21.4n ; n = 0.785 (3) 62 = 61.2 + 21.4n ; n = 0.037 (4) 90 = 61.2 + 21.4n ; n = 1.346 (5) 31 = 61.2 - 21.4n ; n = 1.4
Therefore, the answer for 45 and 78 is approximately 1 (letter b), for 62 is zero (letter a), and for the last two numbers, more than 1 or two (letter c).