Uri asked six friends how many different foreign countries they'd been to. He recorded 0, 1, 1, 2, 5, and 9 countries visited. What is the mean absolute deviation of countries visited?
Round to the nearest tenth, if needed.
0 0
O 2.7
0 2.9
O 3

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).