Chapter 3 Working with Charts 105
rates. That’s not surprising, but there are a couple of exceptions to that
relationship. For example, a freshman class of students at one univer-
sity showed an average SAT score of 1140 with a graduation percentage
of 58%, which might be lower than would be expected on the basis of
the graduation rates for the other universities with similar average SAT
scores. Which university is it?
Identifying Data Points
When you plot data, you often want to be able to identify individual points.
This is particularly important for values that seem unusual. In those cases, you
might want to go back to the source of the data and check to see whether there
were any anomalies in how the data were collected and entered. You may have
already noticed that if you pass your mouse cursor over the selected data points
in the BigTen scatter plot, a screen tip appears to identify the data series name
as well as the pair of values used in plotting the point (see Figure 3-20).
Figure 3-20
Screen tip
identifying
a data point
Although this information is interesting and potentially helpful, it doesn’t
tell you more about the source of the data point. For example, which uni-
versity supplied this particular combination of SAT score and graduation
