Use measures of center and measures of variability to draw informal comparative inferences about two populations

What you'll learn

1. Choose an appropriate measure of center (mean or median) and justify that choice based on the shape of a data distribution or the presence of outliers.
2. Choose an appropriate measure of variability (MAD or IQR) and explain how it corresponds to the chosen measure of center.
3. Compute mean, median, MAD, and IQR for a small data set drawn from a random sample, and use those measures to describe each of two populations.
4. Write informal comparative inference statements that use both center and variability together -- including appropriately hedged language such as "generally," "tends to be," "on average," and "based on this sample."
5. Explain why larger random samples produce more reliable comparisons than smaller samples, and why the word "informal" is important in "informal inference."