Question

If the average (arithmetic mean) of 4 and x is equal to the average (arithmetic mean) of 2 , 8, and x, what is the value of x?​

Answer 1

x = 8

Explanation:

the average is calculated as

average =
`(sum)/(count)`

given that the average of both sets of data are equal then

`(4+x)/(2)` =
`(2+8+x)/(3)` ( cross- multiply )

3(4 + x) = 2(10 + x) ← distribute parenthesis on both sides

12 + 3x = 20 + 2x ( subtract 2x from both sides )

12 + x = 20 ( subtract 12 from both sides )

x = 8