Need help understanding equations:

A survey of college students was conducted during final exam week to assess the number of cups of coffee consumed each day. The mean number of cups was 2 with a standard deviation of 0.5 cups. The distribution was normal. Make sure you do NOT round when answering any of these questions and that you use your Jackson e-book for exact values. When applicable, show ALL work for full points.

1. If Nancy had 3 cups of coffee, what is her z score?
2. What proportion of students drank more cups of coffee than Nancy?
3. How many cups of coffee would an individual at the 33^th percentile rank drink? (do NOT round your final answer)
4. Determine the proportion of scores that fall between the positive z-scores of 0.75 and 1.25.