Question

Find the mean of the given frequency distribution table

Answer 1

Mean = 32.8

Explanation:

Mean is given as Mean = (Σfx)/Σf

First, find the mid-point, x, of each class, and multiply by the frequency (f) of the class to get fx:

Class ==> f ==> x ==> fx

0-10 => 3 => 5 => 15

10-20 => 8 => 15 => 120

20-30 => 10 => 25 => 250

30-40 => 15 => 35 => 525

40-50 => 7 => 45 => 315

50-60 => 4 => 55 => 220

60-70 => 3 => 65 => 195

Sum the fx of all classes together to get Σfx:

Σfx = 15 + 120 + 250 + 525 + 315 + 220 + 195 = 1,640

Σf = 3 + 8 + 10 + 15 + 7 + 4 + 3 = 50

(Σfx)/Σf =
`(1,640)/(50)`

(Σfx)/Σf =
`32.8`

Mean = 32.8