1 1. 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. What percentage of 20-29-year-old females have a serum HDL cholesterol level below 39? (Round answer to the nearest hundredth.) 12. 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. What percentage of 20-29-year-old females have a serum HDL cholesterol level above 71? (Round answer to the nearest hundredth.) 13. 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. What percentage of 20-29-year-old females have a serum HDL cholesterol level between 60 and 75? (Round answer to the nearest hundredth.) 14. 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. What is the probability that a randomly selected 20-29-year-old female has a serum HDL cholesterol level below 45? (Round answer to the nearest ten-thousandth, four decimal places.) 15. 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. What is the probability that a randomly selected 20-29-year-old female has a serum HDL cholesterol level between 50 and 60? (Round answer to the nearest ten-thousandth, four decimal places.) Page 2 of 3 RVCC Statistics I Homework 16. 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 25th percentile of the serum HDL cholesterol for a 20-29-year-old female. (Round answer to the nearest thousandth.) 17. 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 ten-thousandth, four decimal places.)