Suppose that a golfer keeps track of how far he hits the ball when he practices his

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Question:

Suppose that a golfer keeps track of how far he hits the ball when he practices his long shots, and he has found over time that his distances have an average of 180 yards and a standard deviation of 20 yards. Suppose that he starts using a new brand of a golf ball and wants to see whether his average distance seems to improve. He hits 64 shots with the new ball and calculates his average distance to be 190 yards. Does this provide strong evidence that the mean of his driving distances is greater than 180 with the new ball?

Problem: A student answers this question by saying “Yes because 190 is larger than 180.”