NOW ASAP I NEED HELP ON THIS FAST PLEASE

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%

This is about circle theorems. someone asap : (

Mr.zimmerman invested $25,000 in an account that draws 1.4 interest, compouneded annually. what is the total value of the account after 15 years