Brad scored 87, 71, 72, 74 and 86 on his five tests during the semester. The average of those scores count for two thirds of his final grade. He has a final exam at the end of the semester that will count for the other one-third. To get a B. his final grade must be greater than or equal to 80 and less than 90 Solve for the range of grades x that he could score on his final exam that would result in him getting a B. Give your answer as an inequality Assume that 100 is the greatest possible grade .