Find the value of y 7,8,2,5,y; mean=5

Value of y = 3

Mean is the average of all numbers. We must add up all the numbers and divide the sum by the numbers there are.

(7 + 8 + 2 + 5 + y) / 5 = 5
(22 + y) / 5 = 5

Perform Cross multiplication.

22 + y       =     5
     5                  1
(22 + y) * 1 = 5 * 5
22 + y = 25

Find y. Transfer 22 to the other side and change its sign.

y= 25 - 22
y = 3.

To check. Substitute y with its value.

(7 + 8 + 2 + 5 + y) / 5 = 5
(7 + 8 + 2 + 5 + 3) / 5 = 5
25 / 5 = 5
5 = 5