What is 3 times 3/4 in multiply fraction

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%

Can somebody 1. what is the formula for finding the vertical distance between two points on a coordinate plane?

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?