The following data represents the percent change in tuition levels at public, four-year colleges (inflation adjusted) from 2008 to 2013 (Weissmann, 2013). Below is the frequency distribution and histogram.

Class Limits

Class Midpoint

Frequency

Relative Frequency

2.2 - 11.7

6.95

6

0.12

11.8 - 21.3

16.55

20

0.40

21.4 - 30.9

26.15

11

0.22

31.0 - 40.5

35.75

4

0.08

40.6 - 50.1

45.35

2

0.04

50.2 - 59.7

54.95

2

0.04

59.8 - 69.3

64.55

3

0.06

69.4 - 78.9

74.15

2

0.04

What was the approximate value of the most frequent change in tuition?