4. A study of State U professors found the time in years a professor spent completing his/her doctoral program was skewed left with a mean of 4.8 years and a standard deviation of 1.6 years. (a) Should we expect the mean to be less than, greater than, or about the same as the median? Explain. (b) Does the Empirical Rule apply for this distribution? Explain. (c) At least what percent of times is between 2 years and 7.6 years? (d) What is the smallest interval guaranteed to capture at least 80% of all times?