3. The weekly number of luxury and compact cars sold by "Honest" Abe Smith at the Auto Mart, a local car dealership, can be represented as the outcome of a bivariate random variable (X, Y) with the nonzero values of its joint probability density function given by y

0 2 3 4 0 .20 .15 .075 .05 .03 X .10 .075 .04 .03 .02 2 .05 .03 .02 .01 .01 3 .04 .03 .02 .01 .01 Al receives a base salary of $100/week from the dealership, and also receives a commission of $100 for every compact car sold and $200 for every luxury car sold.