1. The gross weekly sales at a certain restaurant are a normal random variable with mean $12,500 and standard deviation $2,000. Assume that the gross sales of each week are independent. What is the probability that the total gross sales over the next two weeks exceeds $26,000? 2. The joint density function of X and Y is given by Find the conditional density of X, given Y = y. 3. The random variables X and Y have joint density function f(x,y) = 1 x1, y1. Compute the joint density function of U=XY and VX/Y.