Subtraction 9/4 - 9/8

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? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Can some one explain this i got sent this. is this a threat i’m scared

Landon drove 103.5 miles on tuesday 320.75 miles on wednesday and 186.30 miles on thursday for work his company pays 0.07 $ for each mile he drives he expects to be paid more than $40,000 is he correct explain