ILLUSTRATIVE SAMPLE — fictional or supplied example data.

Provide the source material
Source: The mean is the sum divided by the number of values. The median is the middle value after sorting an odd-sized set. Goal: compare the effect of one unusually large value. Data: 2, 3, 3, 4, 18.

What should you be able to do?
Compare how an unusually large value affects the mean and median.

What is your starting level?
Beginner who can add and divide.

Which question formats help?
Four questions, followed by a clearly separate worked answer key. Include a reasoning mistake to diagnose.