Brian is placing a photograph behind a 12 in by 12 in piece of matting. he positions the photograph so the matting is twice as wide at the top and bottom as it is at sides. the visible area of the photograph is 54 in. what are the the dimensions of the photograph?

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

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%

Which one is true about the hexagons ?