Chapter 10.1, Problem 21HP

To determine

To create a data set and describe the mean change.

Answer to Problem 21HP

The data set is10,10,20,30,70,90,90

The mean will increase.

Explanation of Solution

Given information:

Median lower than mean.

Calculation:

If the test scores are: 10,10,20,30,70,90,90

Total terms=7 (0dd)

Mean is $\frac{10+10+20+30+70+90+90}{7}=\frac{320}{7}=45.7$

Median is $\frac{{(n+1)}^{th}}{2}observation=\frac{7+1}{2}=4^{th}ob=30$

So, here is the set of data having less median than mean.

If we add an unusually high score, the mean of the dataset will increase. It is because value of test score is higher than the mean.