2(length) + 2(width) what does this equal

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%

Answer asap! due in 30 minutes! ! 8th grade math

What is the value of g(8) for the function g(x) in part c? what does this value mean in the context of the situation you described in part c?