Question

What is the value of x if the average of 10, 11, 12 and x is 9?

Answer 1

Answer: The value of x is 3.

Explanation:

Since we have given that

10,11, 12 and x

Average of above numbers = 9

As we know that

Average is given by

`\frac{\text{Sum of observation}}{\text{Number of observation}}\\\\\\(10+11+12+x)/(4)=9\\\\10+11+12+x=9* 4\\\\33+x=36\\\\x=36-33\\\\x=3`

Hence, the value of x is 3.