Answer:
52.8
Step-by-step explanation:
We take the midpoint of the range as, x
Midpoint = (lower + upper) /2
Midpoint, x ___ Frequency, F
15 ___________ 7
45 __________27
75 __________12
105 __________4
The mean :
Σfx / Σf
= [(15*7) + (45*27) + (75*12) + (105*4)] / (7+27+12+4)
= 2460 / 50
= 52.8
