Sinplifique as expressões

Determine whether the samples are independent or dependent. upper a data set includes the morning and evening temperature for the lasta data set includes the morning and evening temperature for the last 90 days.90 days.

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

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.