8. A sample of assistant professors on the business faculty at state-supported institutions in Ohio revealed the mean income to be $72,000 for nine months, with a standard deviation of $3,000. Using Chebyshev's Theorem, what proportion of the faculty earns more than $66,000, but less than $78,000? A. At least 50% B. At least 25% C. At least 75% D. At least 100%