28. The season average price per pound, p, and total season quantity sold, q, of sweet cherries in a regional market can be represented as the outcome of a bivariate random variable (P, Q) with the joint probability density function I(p, q) = .5qe-ql.S+plIIO,ool(q)IIO,ool(P), where p is measured in dollars, and q is measured in millions of pounds.