What is the standard deviation for 9, 8, 1, 11, 1, 12, 9, 12, 4, 12

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?

Harry the hook has 7 1/3 pounds of cookie dough.she uses 3/5 of it to bake cookie. how much cookie dough does she use to make cookie?