What is the value of b on the number line below?

Solve the equation x/4 - 5= -8 -27 -12 -7 12

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%

Ten times the square of a non-zero number is eqaul to ninety times the number