Lesson Two
Lesson
Introduction <br> In the last lesson, we introduced the idea of asking “how much older” and similar questions. <br> For a question like that, we often make distributions of some value for two groups, and then compare the centers of those distributions. Last time, we used dividers and then the median. <br> Now, we will start with another common quantitative tool for the center: the mean. Frequently, when people talk about “the average,” they usually mean the arithmetic mean. <br> In this lesson, you will: Understand mean as a balance point in a distribution Calculate mean and median for a small group Predict the direction of mean and median in symmetrical and asymmetrical distributions Study the effect of outliers on means and medians