You’re a teacher and you have a large class. You look at a frequency distribution graph of their final exam scores and you notice something interesting: the distribution has an approximately normal...

You’re a teacher and you have a large class. You look at a frequency distribution graph of their
final exam scores and you notice something interesting: the distribution has an approximately normal distribution! The mean of the distribution is 78 points (out of 100) and the standard deviation is 7 points.

Out of your entire class, approximately what percentage of them score below 71? Draw your normal distribution and explain how you calculated the percentage.

Approximately what percentage of your students scored between 70 and 90? Draw your normal distribution and explain how you calculated the percentage.

You decide to grade on a curve. That means that the highest 10% of scores get A’s, the lowest 10% of scores get F’s, and the rest of the scores are spread out among the remaining 80%. How low would you have to score in order to get an F in this situation?