Question

Select true or false

- (T/F) A box contains 4 red balls (R) and 3 white balls (W). Sample two balls from the box without replacement. Then P(the 1st ball is R) = P(the 2nd ball is R).

- (T/F) Let X be the total number of tosses of a fair coin right before the 2nd tail appears. Then VarX = 4.

- (T/F) If (X, Y ) is uniformly distributed over the unit disk {(x, y) ∈ IR² : x² + y² ≤ 1}, then P(X + Y > 0) = 2/π.

- (T/F) If (X, Y ) is uniformly distributed over the square [−1, 1]², then X and Y are uncorrelated.

- (T/F) If X ∼ N(1, σ²), Y ∼ N(2, σ²), then P(X > 4) > P(Y > 4).

- (T/F) If X and Y are iid Exp(1) random variables, then min{X,Y} is an Exp(2) random variable.

Answer 1