Question

Consider the following frequency distribution:

Class interval :	5 – 10	10 – 15	15 – 25	25 – 45	45 – 75
Frequency :	6	12	10	8	15

To draw a histogram to represent the above frequency distribution the adjusted frequency for the class 25-45 is
(a) 6
(b) 5
(c) 3
(d) 2

Answer 1

In the given frequency distribution,

Minimum class size = 5 (10 − 5 = 5 or 15 − 10 = 5)

Class size of the class 25–45 = 45 − 25 = 20

Frequency of the class 25–45 = 8

We know

Adjusted frequency of a class = $\frac{\mathrm{Minimum}\mathrm{class}\mathrm{size}}{\mathrm{Class}\mathrm{size}}$ × Frequency of the class

∴ Adjusted frequency for the class 25–45 = $\frac{5}{20}\times 8$ = 2

Thus, in order to draw a histogram to represent the given frequency distribution the adjusted frequency for the class 25–45 is 2.

Hence, the correct answer is option (d).