!Emergency math question!

1. what is the measure of ∠abc? what is the measure of ∠abd?

Solve the equation -9p - 17 =10 a -3 b. 16 c. 18 d -16

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%