Which of the following is equivalent to 30p^4q^3r + 42p^2r - 18p^2q^2r when it is completely factored? a. 3pr(10p^3q^3 + 12p - 9pq^2) b. 6(5p^4q^3r + 7p^2r - 3p^2q^2r) c. 6p^2q^2r(5p^2q + 4) d. 6p^2r(5p^2q^3 + 7 - 3q^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%