You are in an elementary electrical engineering class of 300 students. The instructor tells the class at the beginning of the class that he will be marking on a curve: 10% A, 20% B, 40% C, 20% D, and 10% F. At the end of the term the instructor states that the overall class average is 70 with a standard deviation of 10. Your overall average is 80. What is your grade? Your best friend's overall average is 83. What is her grade? At what point does a student get an F? When grades come out, you find that are 40 As, 70 Bs, 140 Cs, 40 Ds, and 10Fs. You wonder if it is possible that this distribution is taken from the distribution proposed at the start of term.