Question

The following data set is given: 122, 130, 145, 154, 165, 178Adding which number to the set will increase its mean?A) 140B) 148C) 149D) 150

Answer 1

First, let's calculate the mean of the given set.

The mean is given by the sum of all numbers divided by the amount of numbers:

$\begin{gathered} mean=\frac{122+130+145+154+165+178}{6}\\ \\ mean=\frac{894}{6}\\ \\ mean=149 \end{gathered}$

In order to increase the mean, we need to add a number that is greater than the mean.

Looking at the options, the only number that is greater than the mean is 150.

Therefore the correct option is D.