Homework Questions

16 Among coffee drinkers, men drink a mean of 3.2 cups per day with a standard deviation of 0.8 cup. Assume the number of cups per day follows a normal distribution. Compute the minimum number of cups consumed by a heavy coffee drinker if the top 5% of coffee drinkers are considered "heavy" coffee drinkers. (Use the following answer format: #.#)

(b) A study is conducted to assess the impact of caffeine consumption, smoking, alcohol consumption, and physical activity on cardiovascular disease. investigators wanted to assess the accuracy of self-reported smoking status. Participants are asked whether they currently smoke or not. In addition, laboratory tests are performed on hair samples to determine presence or absence of nicotine. The laboratory assessment is considered the gold standard, or truth about nicotine consumption. The data are as follows: Nicotine Absent Nicotine Present Self-reported nonsmoker 82 14 Self-reported smoker 12 52 Compute the sensitivity of self-reported smoking status. (Use the following answer format: #.####)

(c) A study is conducted to assess the impact of caffeine consumption, smoking, alcohol consumption, and physical activity on cardiovascular disease. investigators wanted to assess the accuracy of self-reported smoking status. Participants are asked whether they currently smoke or not. In addition, laboratory tests are performed on hair samples to determine presence or absence of nicotine. The laboratory assessment is considered the gold standard, or truth about nicotine consumption. The data are as follows: Nicotine Absent Nicotine Present Self-reported nonsmoker 82 14 Self-reported smoker 12 52 Compute the specificity of self-reported smoking status. (Use the following answer format: #.####)