Franco has decorating ribbon that is 8 3/4 feet long, to be used for gift packages. Each package requires 2 1/2 feet of ribbon. How many packages can Franco decorate with his ribbon?

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%