An industrial psychologist sought to evaluate the effects of a new profit-sharing incentive plan on

productivity in her firm, a computer assembly plant. The plant had 10 assembly teams. The number of units produced by each team during an 8-week period prior to the beginning of the new incentive plan and for 8 weeks afterward are presented below. Test the hypothesis that the new incentive plan had no effect on productivity.

Team Before After 1 85 80 2 79 3 78 4 80 5 81 6 108 102 7 76 69 9 78 10 74 no a