The following data set is given: 122, 130, 145, 154, 165, 178
Adding which number to the set will increase its mean?

The mean, or average of a data set, is found by adding the data points and dividing the sum by the number of data points. In order to increase the mean of a data set, a value larger than the mean must be added to the data set. Calculate the mean, and then find the answer choice that is larger than the mean:
Mean = (122 + 130 + 145 + 154 + 165 + 178) ÷ 6
= 894 ÷ 6
= 149
Of the choices available, only 150 will increase the mean.