Grade 7 · Unit 5Topic 2 of 2~22 min

Comparing Two Populations

Compare data sets using their centers and how spread out they are.

Step 1 · Learn

Walkthrough

Read this first — it covers the idea in plain language with a worked example.

To compare two groups, look at a measure of center (mean or median) and a measure of spread (range, IQR, or mean absolute deviation).

Worked example

Class A has a mean test score of 80; Class B has a mean of 72. Both have similar spread. What can you infer?

Tip

A difference between groups is more meaningful when it is large compared to how spread out the data is.

Step 2 · Watch

A short video that walks through this topic.

Khan Academy

Pick the right display and compare two data sets.

Step 3 · Practice

Try a worksheet or work through some problems before the quiz.

Step 4 · Check

A couple of questions to make sure this topic stuck. Retake as many times as you want.

Comparing Two Populations

Easy

To compare the typical value of two data sets, which should you compare?