The median of $20, x, 15, 30, 25$ is $0.4$ less than the mean. If $x$ is a whole number, what is the sum of all possible values of $x$?
15 20 25 30
Possible x values Mean Median
37 25.4 25
22 22.4 22
12 20.4 20
Sum of x values = 71
