Question

Look at the table given below:

Marks	0−10	11−20	21−30	31−40
No. of students	6	9	11	4

The true lower limit of the class 21−30 is
(a) 21
(b) 20
(c) 20.5
(d) 21.5

Answer 1

(c) 20.5

To find the true lower limits of the classes, we will draw a continuous frequency distribution table, as given below.

Marks	No. of Students
$-$0.5−10.5	6
10.5−20.5	9
20.5−30.5	11
30.5−40.5	4

Thus, the true lower limit of the class 21−30 is 20.5