The shape of the distribution of the time required to get an oil change at a 10 minute oil change facility is unknown. However, records indicate that the mean time is 11.2 minutes and the standard deviation is 4.8 minutes (a) to compute probabilities regarding the sample mean using the normal model, what size sample would be required?
(b) What is the probability that a random sample of n=45 oil changes results in a sample mean time less than 10 minutes?

Four airplanes carrying a total of 400 passengersarrive at the detroit airport. the airplanes carry, respectively,50, 80, 110, and 160 passengers. a) one of the 400 passengers is selected uniformly at random. let x denote the number of passengers that were on theairplane carrying the randomly selected passenger. find var(x)for x as given in the problemb) one of the 4 airplane drivers is also selected uniformly atrandom. let y denote the number of passengers on the chosen driver’s airplane. find var(y) for y as given in the problem

Find the slope and the y-intercept if there's one and the equation of the line given these two points( 3, 2) and( 3, -4)

The table shows the results of three plays in a football game. what is the net result of the three plays? football game 1st play 5 yards 2nd play -9 yards 3rd play 12 yards