Dental The levels of nicotine in 6 cigarettes were 13.0, 11.8, 15.4, 17.4, 31.2 and 24.3 mg. The mean of these values is A 14.9 B 15.9 C 18.6 D 8.4 💡 Explanation The levels of nicotine in 6 cigarettes were 13.0, 11.8, 15.4, 17.4, 31.2 and 24.3 mg. The mean of these values is ✓ Correct Answer: C. 18.6