Why is 3 times 1/10 less than 3 times 10

Identify an equation in point slope form for the line perpendicular to y=3x+5 that passes through (4,-1)

Which of the following is correct interpretation of the expression -4+13

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%