By now you are adept at calculating averages and intuitively can estimate whether something is “normal” (a measurement not too far from average) or unusual (pretty far from the average you might expect). This class helps to quantify exactly how far something you measure is from average using the normal distribution. Basically, you mark the mean down the middle of the bell curve, calculate the standard deviation of your sample and then add (or subtract) that value to come up with the mile markers (z scores) that measure the distance from the mean.

For example, if the average height of adult males in the United States is 69 inches with a standard deviation of 3 inches, we could create the graph below.