4. For the function g(x) shown graphed below, over which of the following intervals is g(x) > 0? (1) -4 < x <-1
(2) 0 (3) -3 < x < 5
(4) -1

The discrete random variables x and y take integer values with joint probability distribution given by f (x, y) = a(y−x+1) 0 ≤ x ≤ y ≤ 2 or =0 otherwise, where a is a constant. 1 tabulate the distribution and show that a = 0.1.2 find the marginal distributions of x and y. 3 calculate cov(x, y).4 state, giving a reason, whether x and y are independent. 5 calculate e(y|x = 1).