Which of the statements below is true for the following set of numbers?
20, 15, 50, 85, 75, 60

At the newest animated movie, for every 9 children, there are 4 adults. there are a total of 39 children and adults at the movie.

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%

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).