Question

If the mean of x,x+3, x+6,x+9 ,and x+12 is 16 then find the mean of first three observations

Answer 1

Explanation:

(x + x+3 + x+6 + x+9 + x+12)/5 = 16

5x + 30 = 16*5 = 80

5x = 80 - 30 = 50

x = 10

The observations are -

10 , 13 , 16 , 19 , 22

Mean of first three observations

= (10+13+16)/3

= 39/3 = 13