Question

The average that of 9 number is 15.15 and that of 11 number 17.65. Find the average of all the numbers.

A 16.161.

B 16.0525

c. 16.525

D 16.565​

Answer 1

Correct answer is:- (C) 16.525

Explanation:- 

Average of 9 numbers = 15.15

Sum of 9 numbers = 15.15 × 9 = 136.35 

Average of 11 numbers = 17.65

Sum of 11 numbers = 17.65 × 11 = 194.15 

Sum of 20 numbers = 136.35 + 194.15 = 330.5

Mean of 20 numbers = 330.5 / 20 = 16.525

Therefore, the mean of 20 numbers is 16.525