Question

Find the value of x .

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

Answer 1

51

Explanation:

The mean is obtained by adding up the values in the data set and then divide by the number of values that you added:

`\bar X=\sum{X_i}\\`

Given our mean as 11.5 and n=4:

`\bar X=(1)/(n)\sum{X_i}\\\\\\\\\therefore\sum{X_i}\\=11.5* 4=46`

#Knowing our sum as 65, we can obtain x by subtracting sum of known values from 65:

`x=46-(12.5+-10+-7.5)\\=51`

Hence, the value of x is 51