If f(x) = 0.5(2 - x), what is the value of f(-2)?

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 you me find the missing length. i attached an image.

Anyone? 15m is what percent of 60m; 3m; 30m; 1.5 km?