Events a and b are overlapping. p(a) = 6/17 ; p(b) = 5/17 ; p(a and b) = 3/17 . find p(a or b). show your work!

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%

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

Atoss of a 20-sided die is equally likely to be any integer between 1 and 20 inclusive. what is the variance? provide your answer to two decimal points.