As reported by the U.S. National Center for Health Statistics, the mean serum high-density (HDL) cholesterol level of females 20-29 years old is 53 mg/dL with a standard deviation of 13.4. the variable is normally distributed. Determine the serum HDL cholesterol levels that make up the middle 80% of serum HDL cholesterol levels. (Round answers to the nearest thousandth, three decimal places.) What is the upper and what is the lower level?