Blood Pressure and Platelets Given below are the systolic blood pressure measurements (mm Hg) and blood platelet counts (1000 cells>μL) of the first few subjects included in Data Set 1 “Body Data” in Appendix B. Construct a graph suitable for exploring an association between systolic blood pressure and blood platelet count. What does the graph suggest about that association?

Systolic 100 112 134 126 114 134 118 138 114 124

Platelet 319 187 297 170 140 192 191 286 263 193

The data consists of the blood platelet counts (1000 cells/) and the systolic blood pressures (mm Hg) of a few subjects.

To identify if two variables are associated/related to each other, a scatterplot is constructed.

Any particular pattern depicted by the points on the scatterplot helps to identify if the two variables are related or not.

The following are the steps to plot a scatterplot:

• Make two axes: one horizontal axis and one vertical axis.
• Choose a suitable scale to mark values on the two axes when the platelet counts are considered on the vertical axis and the blood pressureson the horizontal axis.
• Locate the points on the graph corresponding to the values of the blood pressure on the horizontal axis and the values of the platelet count on the vertical axis.
• Label the horizontal axis as “Systolic Blood Pressure” and the vertical axis as “Platelet Count.”

The following scatterplot is constructed:

It can be observed that the points on the plot do not follow any particular pattern and are scattered on the graph.

This indicates that there is no association between the blood platelet count and the systolic blood pressure.