Question

Chandler has the following data:7,1,1,d,18If the mean is 9, which number could d be? 18 Or 33

Answer 1

The mean, m, is computed as follows:

$m=\frac{\text{ sum of the terms}}{\text{ }number\text{ of terms}}$

Substituting with m = 9 and the data, we get:

$\begin{gathered} 9=\frac{7+1+1+d+18}{5} \\ 9\cdot5=27+d \\ 45-27=d \\ 18=d \end{gathered}$