Please help me solve 2,800 divided by 25

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%

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

Show your workcan a right triangle have this sides? *how to prove it without using the pythagorean theorema*