1. In an experiment comparing a new long-distance golf ball with the conventional design, each of 20 golfers hits one drive with each ball. The average golfer in the sample hit the new ball 9.3 yards farther, with a standard deviation of 10.5 yards. At the 0.005 level, evaluate the effectiveness of the new ball in increasing distance. Using the appropriate statistical table, what is the approximate p-value for this test?
2. The idling speed of 14 gasoline-powered genera- tors is measured with and without an oil additive that is designed to lower friction. With the additive installed, the mean change in speed was 123 revolutions per minute (rpm), with a standard deviation of 3.5 rpm. At the 0.05 level of significance, is the additive effective in increasing engine rpm?