The population density of a certain 750 square mile area 1980 was 1077 people per square mile. In 1990the population density was 1137 people per square mileIn 2000, the population density was 1144 people per square mile. In 2010 the population density was 1193 people per square mile. What was the population of this area in 1980 ? a The population was 807240 people . b The population was 807590 people The population was 807750 people The population was 807710 people .

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