Question

The following are average weakly losses of worker-hours due to accidents in 10 industrial plants before and after a certain safety program was put in operation :

$\displaystyle

Before : \qquad 45 \qquad 73 \qquad 46 \qquad 124 \qquad 33 \qquad 57 \qquad 83 \qquad 34 \qquad 26 \qquad 17$

$\displaystyle

After : \ \ \qquad 36 \qquad 60 \qquad 44 \qquad 119 \qquad 35 \qquad 51 \qquad 77 \qquad 29 \qquad 24 \qquad 11

$

Use the 0.05 level of significance to test whether the safety program is effective.