Bell curving grades is common at some post-secondary institutions. Historically, suppose they aim for a mean of 70% and a standard deviation of 10%. This year, the mean was only 63% and the standard deviation 7%. a. If Amy got an 80% this year, what was her z-score using the standard deviation and mean from this year? b. Using the historic mean and standard deviation, as well as your calculated z-score, find Amy's curved mark. c. Ben took the class this year as well and is only getting a 46%. Will he be passing with the curve applied? d. What mark this year would be exactly a 50% after the curve