Question

Look at the frequency distribution table given below:

Class interval	35 – 45	45 – 55	55 – 65	65 – 75
Frequency	8	12	20	10

The median of the above distribution is ______.

Options

• 56.5

• 57.5

• 58.5

• 59

Answer 1

The median of the above distribution is 57.5.

Explanation:

We have

Class interval	35 – 45	45 – 55	55 – 65	65 – 75
Frequency	8	12	20	10
Cumulative frequency	8	20	40	50

Here, N = 50 ⇒ `N/2 = 25`, which lies in class interval 55 – 65.

Medain = `l + {h xx ((N/2 - cf))/f}`

= `55 + ((65 - 55))/20 xx (25 - 20)`

= 57.5