Question

If the mean of 5, 7, 8, 10 and x is 9, then the value of x is

Answer 1

Step-by-step explanation:

Given, arithmetic mean =9

A.M. =Sum/Number

A.M. = 5+7+9+x/4

⇒9=21+x/4

⇒x=36−21

⇒x=15

Answer 2

Step-by-step explanation:

mean = sum of observation / no. of observation

9 = 5 + 7 + 8 + 10 +x / 5

9×5 = 30 + x

45 - 30 = x

15 = x