Question

The mean of a,b,c,and d is 9 and the mean of a,b,c,d,e and f is 12. find the mean of e and f​

Answer 1

mean of e + f = 18

Explanation:

(a + b + c + d)/4 = 9 Multiply by 4

a + b + c + d = 9 * 4 = 36

(a + b + c + d + e + f ) / 6 = 12

but a + b + c + d = 36

(36 + e + f)/6 = 12 Multiply by 6

36 + e + f = 72 Subtract 36 from both sides

e + f = 36 Divide by 2 to find the mean.

(e + f)/2 = 36/2

mean of e + f = 18