are used everyday in life, and are very important in the everyday world. One important use of is to summarize a collection of data in a clear and understandable way. For example, if a psychologist gave a personality test measuring shyness to all 2500 students attending a small college, How might these measurements be summarized? There are two basic methods: numerical and graphical. Using the numerical approach one might compute such as mean and standard deviation. These convey information about the average degree of shyness and the degree ....