The function
models the cost in dollars, c of 1 ounce of a certain chemical used in a laboratory. x represents the number of years since 2010.
Part A: Does the cost of the chemical increase or decrease over time, and by what percentage per year does it do so?

Part B: How much does an ounce of the chemical cost in 2018?

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).