Hello, here is a question from my homework for Probability and Statistics. Please show the solution with full explanation. Thank you

4- A college placement ofce conducted a survey of 100 engineers who had graduated from Stanford University. For these engineers, the mean salary was computed to be $72,000 with a standard deviation of $8,000. What percentage of these engineers earn more than $96,000 or less than $48,000. Use the Tchebysheff' s theorem