In this free online video program, "students will advance from histograms through smooth curves to normal curves, and finally to a single normal curve for standardized measurement, as this program shows ways to describe the shape of a distribution using progressively simpler methods. In a lesson on creating a density curve, students also learn why, under steadily decreasing deviation, today’s baseball players are less likely to achieve a .400 batting average." This individual video is accessed by scrolling down to the "Individual Program Descriptions - 4. Normal Distributions" and click the "VOD" icon at the top-right of the description.