# Box-and-Whisker Plots

Students learn to make a box-and-whisker plot for a given data set using the following steps. First, write the data set in order from least to greatest. Next, find the second quartile, which is the median for the entire data set. Next, find the first quartile, which is the median for the lower half of the data set, and find the third quartile, which is the median for the upper half of the data set. Next, find the least and greatest numbers in the data set. Next, draw a number line with vertical lines at the first, second, and third quartiles, and connect the endpoints of the vertical lines to make a "box". Next, plot the least number in the data set and connect it to the box with a segment, and plot the greatest number in the data set and connect it to the box with a segment, to make "whiskers".