Answer:
7.92 m.
Step-by-step explanation:
Mean height = ∑(f . x) / ∑f where x is the midpoint and f the frequencies
The midpoints for the heights are:
2 for frequency 8 ( 0 + 4)/ 2 = 2
6 for .. 21
10 for .. 12
14 for .. 7
18 for .. 2
So the mean is:
[(2*8) + (6*21) + (10*12) + (14*7) + (18*2) ] / (8 + 21+12+7+2)
= 396 / 50
= 7.92 m.
