Me i need a respond for each of these quetions

Answer this question! 30 points and brainliest! only if you know the answer.

Simplify the expression and find the missing terms. the simplest form of has in the numerator and in the denominator.

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%