Suppose 110 geology students measure the mass of an ore sample. Due to human error and limitations in the reliability of the balance, not all the readings are equal The results are found to closely approximate a normal curve, with mean 83 g and standard deviation 2 g. Use the symmetry of the normal curve and the empirical rule
as needed to estimate the number of students reporting readings between 81 g and 85 9.
The number of students reporting readings between 81 g and 85 g is
(Round to the nearest whole number as needed)

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

Solve each quadratic equation by factoring and using the zero product property. 14x - 49 = x^2

The numbers on a football field indicate 10 yard increments. you walk around the perimeter of a football field between the pylons. you walk a distance of 30623 yards. find the area and perimeter of the indicated regions. write your answers as mixed numbers, if necessary. a. one end zone: perimeter: yd area: yd2 b. the playing field (not including end zones): perimeter: yd area: yd2 c. the playing field (including end zones): perimeter: yd area: yd2