The X-Factor in golf performance. Many golf teaching professionals believe that a greater hip-to-shoulder differential angle during the early downswing—dubbed the “X-Factor”—leads to improved golf performance. The Journal of Quantitative Analysis in Sports (Vol. 5, 2009) published an article on the X-Factor and its relationship to golfing performance. The study involved 15 male golfers with a player handicap of 20 strokes or fewer. The golfers were divided into two groups: 8 golfers with a handicap of 10 strokes or fewer (low-handicapped group) and 7 golfers with a handicap between 12 and 20 strokes (high-handicapped group). The X-Factor, i.e., the hip-to-shoulder differential angle (in degrees), was measured for each golfer at the top of the backswing during his tee-shot. The researchers hypothesized that low-handicapped golfers will tend to have higher X-Factors than high-handicapped golfers. The researchers also discovered that the sample data were not normally distributed. Consequently, they applied a nonparametric test.

a. What nonparametric test is appropriate for analyzing these data?

b. Specify the null and alternative hypotheses of interest in the words of the problem.

c. Give the rejection region for this test, using a = .05.

d. The researchers reported a p-value of .487. Use this result to draw a conclusion. Applying the Concepts—Intermediate