CHAPTER 16 Getting Straight Talk on Straight-Line Regression 219
Creating a scatter plot
It’s not easy to identify patterns and trends between weight and SBP by looking at
a table like Table 16-1. You get a much clearer picture of how the data are related
if you make a scatter plot. You would place weight, the independent variable, on
the X axis, and SBP, the dependent variable, on the Y axis, as shown in
Figure 16-3.
Examining the results
In Figure 16-3, you can see the following pattern:»
» Low-weight participants have lower SBP, which is represented by the
points near the lower-left part of the graph.
Participant Study ID
Body Weight (kg)
SBP (mmHg)
14
71.8
116
15
90.2
115
16
105.4
133
17
100.4
128
18
80.9
128
19
81.8
105
20
109.0
127
FIGURE 16-3:
Scatter plot of
SBP versus body
weight.
© John Wiley & Sons, Inc.