29. On a statistics test students were asked to construct a frequency distribution of the blood creatine levels (Units/liter) for a sample of 300 healthy subjects. The mean was 95 and the standard deviation was 40. The following class interval widths were used by the students:

a. 1

b. 5

c. 10

d. 15

e. 20

f. 25 Comment on the appropriateness of these choices of widths.