why is it important to compare proportion or percent instead of raw numbers when analyzing data in a two-way table

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%

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?

If x-1 and x+3 are the factors of x3+10x2+ax+b find a and b