Coach Smith wants to paint his classroom walls red. Each wall is 25 feet long and 9 feet tall. The janitor says he can only order the paint in boxes that contain 3 small cans. One box is used to paint a 125 square foot on the wall. How many cans will be used to paint all the walls in the room?

The area of a 25-inch tv screen is 300 square inches. the area of a 40-inch tv screen is 768 square inches. the are of the smaller screen is what percent of the area of the larger screen?

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.

Se tiene en una caja de canicas 10, 4 blancas y 6 negras ¿cual es la probabilidad que en 2 extracciones con reemplazo sean blancas? ¿cual es la probalidad que en 2 extracciones sin reemplazo sean negras?