For the data set 7, 5, 10, 11, 12, the mean, x, is 9. What is the standard deviation?

A. 2.9

B. 6.8

C. 2.6

D. 8.5

Fiona and her friends are playing a game by guessing where a coin will land when it is randomly dropped inside the square shown below. fiona guesses that the coin is likely to land in the blue area. which explains whether or not fiona is correct and why?

Nikolas calculated the volume of the prism. his work is shown below.

Joanie wrote a letter that was 1 1/4 pages long. katie wrote a letter that was 3/4 page shorter then joagies letter. how long was katies letter