1. A sample of assistant professors in the business faculty at state supported institutions in Ohio revealed the mean income to be $70,203 for 9 months with a standard deviation of $3,312. Using Chebyshev's Theorem, what proportion of the faculty earns more than $63,579 but less than $76,827?
At least 25%
At least 75%
At least 100%
At least 50%
2. The distribution of a sample of the outside diameters of PVC gas pipes approximates a symmetrical, bell-shaped distribution. The arithmetic mean is 13.0 inches, and the standard deviation is 2.0 inches. About 68 percent of the outside diameters lie between what two amounts?
7.5 and 12.0 inches
11.5 and 12.5 inches
11.0 and 15.0 inches
10.0 and 11.5 inches