I need help it’s a quiz

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%

Which equation is y = -6x2 + 3x + 2 rewritten in vertex form?

1/2+1/6-3/4 simplify the given expression leaving the answer in improper fraction form.