Calculation for Discrete Series or Ungrouped Data
where,
f = frequency
X = variable
In a survey of 50 chemical industries, the following data was collected about the level of profits attained by them:
X_{i} = Level of profit (Rs. lakh) earned during 20x1-x2
f_{i} = No. of companies that earned X_{i} amount of profit
X_{i}f_{i}
20
16
24
25
31
12
15
8
7
240
192
175
248
Total
50
1095
The arithmetic mean is
Thus, the average profit of the chemical industry is Rs.21.90 lakh