Question

What number must be added to 15,-6, and 12 to have a mean of 5? Explain.

Answer 1

You need to add a -1

We can find this by setting up the equation like so

x + (-6) + 12 + 15 / 4 = 5

x + 21 = 20

x = 20 -21

x = -1

Now if we insert -1 where x is located in the equation, you will get a means of 5