Question

A golf club manufacturer claims that golfers can lower their scores by using the manufacturer's newly designed golf clubs. Eight golfers are randomly selected and each is asked to give his or her most recent score. After using the new clubs for one month, the golfers are asked again to give their most recent score. The scores for each golfer are given in the table below. Is there enough evidence to support the manufacturer's claim? Let d = (golf score after using the newly designed golf clubs)—(golf score before using the newly designed golf clubs). Use a significance level of a = 0.01 for the test. Assume that the scores are normally distributed for the population of golfers both before and after using the newly designed clubs. Golfer Golfer Score (old design) Score (new design) 1 2 3 4 5 91 74 72 89 75 90 | 77 71 87 | 76 6 7 92 | 90 88 86 8 81 75 Copy Data Step 2 of 5 : Find the value of the standard deviation of the paired differences. Round your answer to one decimal place.

Answer 1

пеw diff: (d)=x1-x2 0 JOUAWNO NT+ o 9.00 1.00 4.00 1.00 16.00 16.00 36.00 zd2-84 total meandbar a degree of freedom -n-1 Std deviaiton So=(7d-difin)/(n-1) = std error=Se=Sohn Id=14 1.7500 7.000 2.9155 1.0308

from above standard deviation =2.9

(test statistic = 1.707 please try 1.698 if this comes wrong)

Decision rule: reject Ho if test statistic t>2.998

fail to reject Ho