Suppose that the mean G.P.A. of a group of high school students is 3.0, with a standard deviation of 0.3. Their Math SAT scores have a mean of 500 with a standard deviation of 100. If the joint distribution is a bivariate normal with p=0.4, find the probability that a student has a Math SAT above 600, given that her G.p.a. is 3.5.