Question 7 Courtney and Kelly began arguing about who did better on their tests, but they couldn't decide who did better given that they took different tests. Courtney took a test in Science and earned a 78.3, and Kelly took a test in Math and earned a 62.9. Use the fact that all the students' test grades in the Science class had a mean of 72.9 and a standard deviation of 11.5, and all the students' test grades in Math had a mean of 64.3 and a standard deviation of 9.4 to answer the following questions. a) Calculate the z-score for Courtney's test grade. x= b) Calculate the z-score for Kelly's test grade. 2= c) Which person did relatively better? Courtney Kelly They did equally well.