How it works
Look at the dots first. The shape and the job pick the number.
If the data is fairly even, the mean and the median are about the same.
One far-away dot pulls the mean, so the median is a better choice then.
Worked examples
About the same
- Minutes: 19, 17, 16, 16, 18, 13.
- The mean and the median are close.
- Either number tells the story.
One far dot
- Heights are all near 55 except one 66.
- The 66 pulls the mean up.
- The mean is a poor choice here.
Why
- A single far-away value changes the mean a lot.
- The median stays in the middle.
- Use the median.
A taste of the worksheet
These are the first problems of set A. The printable sheet has many more, with an answer key.
- The mean is a good measure of the typical value here.
- Compare the mean of this data with its median.
- Why is the mean a poor choice for a typical value here?
- The median is the middle of the dots. What is the median of this data? Answer: ___
- The top plot is Class A and the bottom plot is Class B. Which class should use the median?