WILL GIVE BRAINLIEST! A soil supplement that weighs 16 lb contains iron, potassium, and mulch. The supplement contains thirteen times as much mulch as iron and twice as much potassium as iron. Find the amount of mulch in the soil supplement.

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%