17.11 Quick revision questions

Consider again the model for tree diameters in Example 17.7 (Aedo-Ortiz, Olsen, and Kellogg 1997): a normal distribution with \(\mu=8.8\) inches, and \(\sigma=2.7\) inches.

1. A tree diameter of 7.9 inches corresponds to a \(z\)-score (to two decimal places) of:
   
2. The probability that a tree has a diameter less than 7.9 inches is:
   
3. The probability that a tree has a diameter greater than 7.9 inches is:
   
4. A tree diameter of 9 inches corresponds to a \(z\)-score (to two decimal places) of:
   
5. The probability that a tree has a diameter less than 9 inches is:
   
6. The probability that a tree has a diameter greater than 9 inches is: