The mean of four numbers a ,b, c, and d is 8 and mean of seven numbers x , y ,z ,a, b, c and d is 12 . Find the mean of x, y and z.

17.33 or 17 1/3

Step-by-step explanation:

(a + b + c + d) / 4 = 8

(a + b + c + d) = 32

((a + b + c + d) + (x + y + z)) / 7 = 12

(a + b + c + d) + (x + y + z) = 84

32 + (x + y + z) = 84

(x + y + z) = 52

Mean of x, y, z:

(x + y + z) / 3 = mean

52 / 3 = mean

17 1/3 = 17.33 = mean

7

step-by-step explanation: