How to do that i don’t get it

The value √10 and √15 are plotted on the number line

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%

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)