Question

Derrick needs to figure out how he’s doing on his test scores so far this year. You can help by calculating the mean and the median to get an overall picture of his scores. Below are all of his scores: 25, 40, 68, 85, 95, 98, 70, 78, 85, 100 What is Derrick’s mean test score so far? What is Derrick’s median test score so far? Which gives a better picture of his scores?

Answer 1

Answer: Derrick’s mean test score= 74.4

Derrick’s median test score = 81.5

Better picture of his scores is given by Median.

Explanation:

The given data : 25, 40, 68, 85, 95, 98, 70, 78, 85, 100

`\text{Mean}=\frac{\text{Sum of all observations}}{\text{Number of observations}}\\\\\Rightarrow\ \text{Mean}=(744)/(10)=74.4`

For Median , Arrange the data in order

25, 40, 68, 70, 78, 85, 85, 95, 98, 100

Median = Mean of two middle most value

`\text{Median}=(78+85)/(2)=81.5`

Since the data set has outlier (25) and mean is affected by outlier.

So the better picture of his scores given by median value.