Comparative Inferences About Two Populations Worksheets, Grade 7 (7.SP.B.4) – Free PDF + Answer Key

First page of the comparative inferences about two populations practice worksheet

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PDFs print on US Letter paper. Free for classroom and home use.

Watch: Mean, Median, Mode, and Range Explained Clearly

Key idea

Two random samples → compare means → divide the gap by the MAD → then conclude. Under 1 MAD, the gap is inside the ordinary variation and supports no claim. Above 2 MADs, it is larger than the natural wobble and supports a claim about the populations.

Sample problems

Sample A has mean 14 and sample B has mean 18. What is the gap?
Sample A is 12, 13, 14, 15, 16. Find its MAD.
Express the gap as a multiple of that MAD.
Is that above or below 2 MADs? What does it let you conclude?

Common mistakes to watch for

Compared the largest values from each sample instead of the means.
Concluded the two SAMPLES differ and stopped. Random samples let you say something about the populations behind them, which is the point of the exercise.
Assumed the MAD would be similar to question 2. Same mean, very different spread — the mean tells you nothing about the MAD.

The answer key explains each one, so you can tell what a wrong answer means.

How to use this set

Teach with the slides (about 15 minutes), or watch the video together.
Practice with the worksheet. Questions climb from fluency to application to reasoning.
Check understanding with the exit ticket, and send the homework home.
Mark with the answer key — each answer shows the steps and the most likely mistake.