joel biked 9 miles east and then 12 miles north. If he biked to his starting point ising the most direct route, how many miles would he ride all together?

If 10 men take 18 days to mow 60 acres of grass, how long will 15 men take to mow 80 acres?

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%

Answer! if you don’t mind, can you explain