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
