The Table Below Shows the Weights, in Pounds, of Seven $\alpha$

The table below shows the weights, in pounds, of seven subjects before and after following a particular diet program for three months. Does the sample evidence suggest that the diet program is effective in reducing weight? Use the $\alpha$ =0.01 level of significance. Assume that the differenced data come from a population that is normally distributed with no outliers.
$\begin{array} { r | c c c c c c c } \text { Subject } & \text { A } & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } & \text { G } \\\hline \text { Before, } \mathrm { X } _ { \mathrm { i } } & 174 & 193 & 190 & 151 & 177 & 182 & 158 \\\hline \text { After, } \mathrm { Y } _ { \mathrm { i } } & 167 & 184 & 188 & 156 & 163 & 184 & 146\end{array}$