ABSTRACT
Recall that continuous random variables take values in subintervals of the real line (ideally at least). In many cases, those values tend to distribute across the line in a roughly symmetrical hill shape, with most of the observations near the center, and successively fewer as you move away from the center. Consider for example Figure 1(a), which is a scaled histogram of a large set of 291 National League batting averages on August 5, 2008. You may open up the first of the two closed cells above the figure to see the data that produced the plot. The center of the distribution seems to be around .270, and the great majority of the observations are between about .190 and .350, that is, about .080 on either side of the center.
