Question

Given a set `{13, x ,-1, 11}`, for what x would the mean of the set be 3?

Answer 1

`x=(-11)`

Explanation:

Sum: `13+x+(-1)+11 = 23+x`

Mean: `("Sum")/("Count") =(23+x)/4`

If Mean `=3`
`color(white)("XXX")(23+x)/4=3`

`color(white)("XXX")23+x=12`

`color(white)("XXX")x=-11`