The Table Below Shows the Weights of Seven Subjects Before

Essay

The table below shows the weights of seven subjects before and after following a particular diet for two months. $$\begin{array} { c | c c c c c c c } \hline \text { Subject } & \text { A } & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } & \text { G } \\\hline \text { Befare } & 176 & 160 & 180 & 187 & 172 & 172 & 159 \\\hline \text { After } & 169 & 151 & 178 & 192 & 158 & 174 & 147 \\\hline \text { B-A } & 7 & 9 & 2 & - 5 & 14 & - 2 & 12 \\\hline\end{array}$$ Do the data suggest that the diet is effective in reducing weight? Perform a Wilcoxon signed rank test at the 5% significance level.