Question

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. If a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. What is the margin of error of the sample mean?

Answer 1

Answer: 2.22%

Explanation:

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Answer 2

The formula of the margin of error of the sample mean.
MOE = standard deviation / square root (sample size).

MOE = 0.043 * 15 / square root (15)
MOE = 0.1665

So, the margin of error of the sample mean is 0.17