10.3 = 0.6y how do i find the easy answer?

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%

Find the missing variable for a parallelogram: a = latex: 28in^2 28 i n 2 h = b = 6.3 in (1in=2.54cm)

A(1,1) b(-3,0) c(-4,-1) d(3,-2) drag it to correct position