Question

Following numbers are arrange in ascending order: 11, 13, 15, 19, х + 2, x + 4, 30, 35, 39, 46. Their median is 25. Find the value of x.

Answer 1

Given: The ordered list is 11, 13, 15, 19, x + 2, x + 4, 30, 35, 39, 46 and the median is 25.

Step-wise calculation:

1. There are 10 numbers (n = 10), so the median is the average of the 5th and 6th observations.

2. 5th observation = x + 2, 6th observation = x + 4.

3. Median = `((x + 2) + (x + 4))/2` 

= `(2x + 6)/2` 

= x + 3

4. Set x + 3 = 25

x = 25 – 3

x = 22