To make a point, a professor marks grades on ping-pong balls and throws them into a box. The grades are normally distributed with a mean 70 and a standard deviation of 9. Students in the class then drew a ball out of the box for a grade. Assuming each ball was put back into the box after it was drawn:
- What was the probability of getting a score above 92?
- What was the probability of getting a score between 70 and 81?
- What was the probability of getting a score below 58?