Question

Find the mean of the following data. C.I : 0–10 10–20 20–30 30–40 40–50 f : 8 10 12 7 5

Answer 1

£f=42
£fx=8×5+15×10+25×12+35×7+45×5=40+150+300+245+225=960
mean=960/42=160/7=22.85

Answer 2

Find the total :

Total = (8 x 5) + (10 x 15) + (12 x 25) + (7 x 35) + (8 x 5)

Total = 960

Find the total frequency:

Total Frequency = 8 + 10 + 12 + 7 + 5

Total Frequency = 42

Find the mean:

Mean = Total ÷ Frequency

Mean = 960 ÷ 42 = 22.86

Answer: The mean is 22.86