Please help, I don't understand how to do this equation

Consider the graph of the exponential function y=3(2)×

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 20 points and brainiest ! on the board, your teacher writes an example of how to find the median. one of the numbers is erased, leaving what is shown, 18, 30, 26,12 22. what is the median? a. 10 b. 20 c. 24 d. 28