Arithmetic Means, Weighted Averages, Medians, and Modes In this section, you will learn how to: • Calculate arithmetic means • Find the value of an unknown score when given all the other scores and an average • Calculate medians • Calculate modes There are three types of averages: arithmetic means, medians, and modes. When you find your semester grade by adding all of your scores together and dividing by the number of scores, you are finding an arithmetic mean. Suppose that you earned the following grades during a semester: 86, 98, 92, 79, and 97. To find your final grade, you add all the scores together and divide by 5, which is the number of scores. Suppose, however, you want to earn at least a 90% for the semester and your first four test grades are 91, 87, 88, and 94. What must you score on the fifth test to earn an average of 90% for the entire semester? Most SAT problems require knowing how to solve the second type of problem....