10-34. The "spring-like effect" in a golf club could be deter- Question 2 mined by measuring the coefficient of restitution (the ratio of the outbound velocity to the inbound velocity of a golf ball fired at the clubhead). Twelve randomly selected drivers pro- duced by two clubmakers are tested and the coefficient of res- titution measured. The data follow: X₁0.8161 Club 1: 0.8406, 0.8104, 0.8234, 0.8198, 0.8235, 0.8562, = 0.000471 0.8123, 0.7976, 0.8184, 0.8265, 0.7773, 0.7871 Club 2: 0.8305, 0.7905, 0.8352, 0.8380, 0.8145, 0.8465, X=0.8271 0.8244, 0.8014, 0.8309, 0.8405, 0.8256, 0.8476 52 = 0.000305 •Test the hypothesis that both brands of clubs have equal mean coefficient of restitution. Use a = 0.05. Before doing a t-test, you must first perform the Variance test to determine if variances are equal. •Therefore, you should have 2 hypothesis tests: Test on Variances and Test on Means. Interpolate value from F-table.

Fig: 1