Page:Online Statistics Education.pdf/40

 by David M. Lane and Heidi Ziemer

Prerequisites • Chapter 1: Variables

Learning Objectives
 * 1) Define “distribution”
 * 2) Interpret a frequency distribution
 * 3) Distinguish between a frequency distribution and a probability distribution
 * 4) Construct a grouped frequency distribution for a continuous variable
 * 5) Identify the skew of a distribution
 * 6) Identify bimodal, leptokurtic, and platykurtic distributions

Distributions of Discrete Variables

I recently purchased a bag of Plain M&M's. The M&M's were in six different colors. A quick count showed that there were 55 M&M's: 17 brown, 18 red, 7 yellow, 7 green, 2 blue, and 4 orange. These counts are shown below in Table 1.

Table 1. Frequencies in the Bag of M&M's

This table is called a frequency table and it describes the distribution of M&M color frequencies. Not surprisingly, this kind of distribution is called a frequency distribution. Often a frequency distribution is shown graphically as in Figure 1. 40