A sporting goods store sells soccer balls for a regular price of $40 each. If a team buys 20 or more soccer balls, the store offers a discount of 15% off the price of each soccer ball.
How much more will it cost a team to buy 20 soccer balls than to buy 15 soccer balls?
$80
$100
$170
$200

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).