a set of 100 values has a normal distribution with a mean of 400 and a standard deviation of 30. find the interval about the mean within which 60% of the data lies.

Complete the standard form of the equation that represents the quadratic relationship displayed above, where a, b, and c are rational numbers.

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

A50% increase followed by 33 1/2% decrease