Pr 2 7100 SolutionLet X and Y be the number of hours that a

Solution

Let X and Y be the number of hours that a randomly selected college student spends studying calculus and physics, respectively during a semester.

Given:

E(X)=50, E(Y)=20

Var(X)=50, Var(Y)=30 and Cov(X,Y)=10.

Let Z be the number of hours that these 100 students spend studying calculus and physics during the semester.

The approximate value of P(Z<7100)=1