Operation Manual

Chapter 12: Statistics 218
Boxplot
Boxplot (Ö)(regular box plot) plots one-variable data. The whiskers on the plot extend from the
minimum data point in the set (minX) to the first quartile (Q1) and from the third quartile (Q3) to the
maximum point (maxX). The box is defined by Q1, Med (median), and Q3.
Box plots are plotted with respect to
Xmin and Xmax, but ignore Ymin and Ymax. When two box plots
are plotted, the first one plots at the top of the screen and the second plots in the middle. When three
are plotted, the first one plots at the top, the second in the middle, and the third at the bottom.
NormProbPlot
NormProbPlot (Ô) (normal probability plot) plots each observation X in Data List versus the
corresponding quantile z of the standard normal distribution. If the plotted points lie close to a straight
line, then the plot indicates that the data are normal.
Enter a valid list name in the
Data List field. Select X or Y for the Data Axis setting.
• If you select X, the TI-84 Plus C plots the data on the x-axis and the z-values on the y-axis.
• If you select Y, the TI-84 Plus C plots the data on the y-axis and the z-values on the x-axis.
Defining the Plots
To define a plot, follow these steps.
1. Press y ,. The
STAT PLOTS menu is displayed with the current plot definitions.