How much do you smoke?

I Notice... That the median for the males is 13.5 cigarettes per day and the median for females is 10 cigarettes per day. This indicates that males smoke on average 3.5 more cigarettes per day than females. That the maximum and minimum values for number of cigarettes smoked per day for both males and females are the same ( 2 cigarettes and 25 cigarettes). The lower and upper quartiles as well as the medians are all higher for males than for females, indicating that males may tend to smoke more cigarettes per day than females. That the middle 50% of number of cigarettes for males is shifted positively by 3.5 cigarettes per day from females

I notice... That the range of the middle 50% for males is larger than that of females (7 cigarettes vs 10 cigarettes) indicating that males have more variation in amount of cigarettes smoked per day and females are more consistent. That there is a small peak for female cigarettes smoked per day where 4 females smoke 12 cigarettes per day. That the male data has two peaks, one in the middle 50% of 3 males smoking 10 cigarettes per day, and another at the maximum of 25 cigarettes per day. The male data is flatter and more evenly spread than the female data. This indicates that the number of cigarettes smoked by males per day is more variable than females. That the females graph is positively skewed by an extreme value where one female smokes 25 cigarettes. I believe this is extreme as there is a gap between this value and the next which is 20 cigarettes per day. The males graph is relatively symmetrical, indicating that the values for the males are consistent across the range.

Conclusion 50% of the males data is above 75% of the females data for number of cigarettes smoked per day. This indicates that males tend to smoke more cigarettes per day than females in Chirstchurch in However the distance between the medians (3.5 cigarettes) is not at least one third of the overall visible spread (13 cigarettes). Therefore I am not very confident in my call that back in the populations males tend to smoke more than females in 2011.

Sampling variation If I was to repeat this sampling process again I would expect the characteristics of the samples to be different but that I would still be able to make the call that males tend to smoke more than females in Christchurch in 2011.

Inference I expected to find that males tend to smoke more than females per day because they are larger and therefore they would need to have more nicotine for their addiction. The results of my investigation showed that this was true. I have more confidence in the results of my investigation as there is a physical reason why males would smoke more than females.