The variance of X must be non-negative; the variance of Y must be ...

[rl]

The variance of X must be non-negative; the variance of Y must be non-negative; hence the covariance of X and Y must be non-negative.
  Indicate whether the statement is true or false

Question 2

If you add two single probability distributions together you get a bivariate distribution.
  Indicate whether the statement is true or false

[nyrave]

Answer to Question 1

F

Answer to Question 2

F

[rl]

Great answer, keep it coming

[mohan]

Gracias!