The owner of a golf course wants to determine if his golf course is more difficult than the one his friend owns. He has 20 golfe
rs play a round of 18 holes on his golf course and records their scores. Later that week, he has the same 20 golfers play a round of golf on his friend's course and records their scores again. The average difference in the scores (treated as the scores on his course - the scores on his friend's course) is 8.9 and the standard deviation of the differences are 11.986. Calculate a 99% confidence interval to estimate the average difference in scores between the two courses.
