A psychology course hs two midterms and a final exam. Midterm 1 is worth 18% of the final grade, Midterm 2 is worth 36% of the final grade, and the final exam is worth 46%. The instructor assigns grades as marls on 100. If a student recieved a mark of 78 on the first mid term and 72 on the second, what mark does she need on the final exam to get a final grade of 80 in the course?