Which expression(s) have a greatest common factor (GCF) of 3xy2 with 42xy4? Select all that apply. A. 6x2y2 B. 15xy2z C. 27x3y2 D. 9xy3

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%