Question

12.5,-10,-7.5,x;the mean is 11.5

Answer 1

Hi!

The correct answer is x = 51.

Explanation:

By definition the mean formula is:

`mean = (x_1 + x_2 + x_3 + ... + x_n)/(n)`

where x are the samples of the data set and n the numbers of elements in the set.

In this case:

• n = 4
• mean = 11.5

Replacing the data on the general formula:

`11.5 = (12.5 - 10 - 7.5 + x)/(4)`

Solving the equation step by step,

`4 * 11.5 = -5 + x}`

`46 = -5 + x}`

`51 = x}`