a We first have to enter the values into lists. Push STAT, choose Edit, and then enter the values in the first two columns.
Group 7A
Having entered the values, we have to instruct the calculator that we want to graph a combination histogram and boxplot. Push 2nd and Y=, and choose one of the plots in the list. Make sure you turn the plot ON, set the type to boxplot, and assign L1 as XList.
In the same diagram, we also want to include a histogram of Group 7A. Therefore, push 2nd and Y=, and choose one of the plots in the list. Make sure you turn the plot ON, choose the type to boxplot, and assign L2 as XList.
Finally, to graph the combination, push GRAPH. Note that you may need to change the x-axis so that it spans the length of the boxplot and histogram.
From the diagram, we see that the data for group 7A data has a relatively small spread and a center at 60. The majority of the data is around the center and with no apparent outliers. The interquartile range is 70-53=17.
Group 7B
Let's repeat the procedure for Group 7B by changing the Plot 1 and Plot 2 to use the values from L2 instead.
Compared to Group 7A, the data distribution has a greater spread and a center at around 60 as well. The data is relatively symmetric with no apparent outliers. The interquartile range is 77-39.5=37.5.
b Which measurements we use depends on if there are any outliers. If there are no outliers the median and mean will be relatively close, which means either one is a good description of the center. If there were outliers present, we should use the median to describe the center.
