Question

The median of the following data is 525. Find the missing frequencies, if it is given that there are 100 observations in the data.

| Class interval | Frequency | Class interval | Frequency |
| 0 - 100 | 2 | 500-600 | 20 |
| 100 - 200 | 5 | 600 - 700 | f2 |
| 200 - 300 | f1 | 700 - 800 | 9 |
| 300 - 400 | 12 | 800 - 900 | 7 |
| 400 - 500 | 17 | 900 - 1000 | 4 |

(A) 8,14

(B) 11, 17

(C) 9, 15

(D) 10, 16

Answer 1

The correct option is: (C) 9, 15

Explanation:

We have given n = 100 + 76 + f1 + f2 = 100

=> f1 + f2 = 24 ...(i)

Since median is 525, so median class is 500 - 600.

=> 25 = (14 - f1) x 5 => 25 = 70 - 5f1 = 5f1 = 45 + f1 = 9

From (i), 9 + f2 = 24 => f2 =24 - 9 = 15