Preliminary Data Analyses Indicates That Use of a Paired Wilcoxon $\mathrm { H } _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$

question 82

Essay

Preliminary data analyses indicates that use of a paired Wilcoxon signed-rank test is reasonable. Perform the hypothesistest by using a paired Wilcoxon signed-rank test. Assume that the null hypothesis is $\mathrm { H } _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$
-The systolic blood pressure readings of ten subjects before and after following a particular diet for a month are shown in the following table.
$\begin{array} { c c c } \text { Subject } & \text { Before } & \text { After } \\ \hline \text { A } & 175 & 162 \\ \text { B } & 192 & 190 \\ \text { C } & 167 & 170 \\ \text { D } & 180 & 180 \\ \text { E } & 161 & 153 \\ \text { F } & 203 & 197 \\ \text { G } & 185 & 191 \\ \text { H } & 176 & 174 \\ \text { I } & 204 & 192 \\ \text { J } & 146 & 150 \end{array}$
At the 1% level of significance, do the data provide sufficient evidence to conclude that the diet has an effect on systolic blood pressure?

---

Definitions:

SSE

Short for Sum of Squared Errors, a measure used in statistics to describe the total deviation of data points from their fitted values in a regression analysis.

Y-intercept

The point where a line, curve, or function crosses the y-axis of a graph.

Dependent Variable

In an experiment or statistical model, the variable that is expected to change as a result of manipulations in the independent variable.

Independent Variable

A factor in a study or simulation that is deliberately altered to see its impact on a variable that depends on it.