In a Study of the Effectiveness of Physical Exercise in Weight

Essay

In a study of the effectiveness of physical exercise in weight reduction, 12 subjects followed a program of physical exercise for two months. Their weights (in pounds)before and after this program are shown in the table. Use a significance level of 0.05 to test the claim that the exercise program has no effect on weight. $$\begin{array} { l l } \text { Before } & 162&190&188&152&148&127&195&164&175&156&180&136 \\\hline \text { After } & 157&194&179&149&135&130&183&168&168&148&170&138\end{array}$$