Kosumi and Heaven began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Kosumi took a test in English and earned a 72.9, and Heaven took a test in Social Studies and earned a 68.2. Use the fact that all the students' test grades in the English class had a mean of 76.5 and a standard deviation of 11.6, and all the students' test grades in Social Studies had a mean of 62.8 and a standard deviation of 8.3 to answer the following questions. a) Calculate the z-score for Kosumi's test grade. z = [Round your answer to two decimal places.] b) Calculate the z-score for Heaven's test grade. z = [Round your answer to two decimal places.] c) Which person did relatively better? Kosumi Heaven They did equally well