Given an interval-level variable, make a grouped frequency distribution.

Use i = 10, start the lowest interval at 20, and report the midpoint,

f, fc

,

%, and %c

. The data are given below—note that they are already organized from low to high.

26 40 47 51 55 61 30 40 47 51 56 61 33 41 47 52 57 62 33 42 48 53 57 64 33 43 48 53 57 65 36 45 48 54 59 65 38 45 48 54 59 67 39 45 50 54 59 72 39 45 50 54 59 73 40 46 50 54 61 75