In Chapter 5, you learned about the normal distribution, the area under the curve, and z-scores. At https://www.mathsisfun.com/data/standard-normal-distribution-table.html they have an interactive normal curve that helps hit home the concepts of the area between the mean and z and the area beyond z. Go to the website and engage with the interactive normal distribution. For example, move the z-score cursor to explore how the percentage of the population changes beyond z. Also, change the options between 0 to Z, Up to Z, and Z Onwards.
After familiarizing yourself with the interactive normal curve and the table, use the table to work out each of the examples (no peeking at the answers until you have calculated your own). After you use the table to get the answers, go back to the interactive curve to adjust the z-score cursor to illustrate the solutions to each of the examples.