Assume that in your Abnormal Psychology class you have earned test scores of 74%, 78%, and 63%, and only one test remains. If you need a mean score of 80% to earn a B for you final grade, is it possible for you to accomplish this? Assume there is no extra credit. Show work and explain why or why not. Hint: you're taking 4 tests total. Using our missing average calculator with our 3 given scores and target average, we get: A 4th score needed of 105. Since the most you can score on an exam is 100, this is impossible.