Question

Approximate the mean for following GFDT.
Data Frequency
60 - 64 1
65 - 69 2
70 - 74 8
75 - 79 10
80 - 84 24
85 - 89 11
90 - 94 9
95 - 99 3
100 - 104 1


mean =


Report answer accurate to one decimal place.