Which angle is congruent to NCM

Solve - pv + 40 < 65 for v solve 7w - 3r = 15 for r

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%

How to use order of operation in 20 divide by 4 multiply 5 = 1