Q1. Find the 95% confidence interval for the standard deviation of the diameter of oranges if a sample of 47 oranges had a standard deviation of 0.18 inches.
Q2. Jimmy Stewart, Tucson's premier weather "guy", claims that the average of the highest temperatures in the U.S. is 93 degrees. A random sample of 35 cities that have high temperatures has an average of 95.8 degrees with a standard deviation of 4.2. Test Jimmy's claim at "alpha" = 0.05.
Q3. Nationwide, the average salary of college graduates is $39,000. A college placement officer feels that the average is higher for graduates at her college. She surveys 31 graduates and finds an average of $40,500 with a standard deviation of $4150. Can her claim be supported at "alpha" = 0.05? What about at "alpha" = 0.01?