Một máy dệt có 800 ống sợi. Xác suất để một ống sợi bị đứt trong khoảng thời gian 1 giờ máy hoạt động là 0,25%. Tìm xác suất để trong khoảng thời gian 1 giờ máy
hoạt động có không quá 2 ống sợi bị đứt.

Margie is practicing for an upcoming tennis tournament. her first serve is good 20 out of 30 times on average. margie wants to know the estimated probability that her first serve will be good at least four of the next six times she serves. how could she design a simulation for this scenario?

The plant were you work has a cylindrical oil tank that is 2.5 feet across on the inside and 10 feet high. the depth of the oil in the tank is 2 feet. about how many gallons of oil are in the tank?

Atoss of a 20-sided die is equally likely to be any integer between 1 and 20 inclusive. what is the variance? provide your answer to two decimal points.