In a random sample of 20 people, the mean commute time to work was 31.7 minutes and the standard deviation was 7.3 minutes. assume the population is normally distributed and use a t-distribution to construct a 95% confidence interval for the population mean mu. what is the margin of error of mu? interpret the results.

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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

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