Question

The mean of the following frequency table is 50. But the frequencies f_i and, f₂ in class 20-40 and 60-80 respectively are missing. Find the missing frequencies.

Classes	0-20	20-40	40-60	60-80	80-100	total
Frequency	17	f1	32	f2	19	120

Answer 1

Let the assumed mean A = 50 and h =20.
Calculation of mean