Biostatistics Assignment Question Sample Assignment

2)

1. Smoking status is a binary or dichotomous variable, since it only has two legitimate possible answers. However, FEV is an ordinal variable.
2. Histogram 1 is smokers, Histogram 2 is non-smokers
3. FEV is more variable in non-smokers
4. You could summarize the frequency of smoking and non-smoking in this particular sample with a pie chart. This could be potentially useful as it would be very easy to read and interpret, yet pie charts usually use 3-7 different samples, so it may be very bland.
5. In histogram 1 of the smokers it shows more of a symmetrical skew, where as the smokers in histogram 2 shows a definite right skew. The median of non-smokers is 2,265 ml. The median of smokers is 3,122.
6. This data shows that smoking decreases the variability of FEV in smokers. Smoking therefore increases their lung capacity, but does not increase it enough to surpass that of non-smokers.
7. My interpretation would definitely change when provided with this information. 9-year olds have smaller lungs, therefore already have a smaller lung capacity. You would expect that the 13 year olds smokers should have a much higher FEV than the non-smokers. This than leads us to believe that smoking has a negative impact on FEV.

3)

1. Two possible reasons cancer deaths in the US continued to rise could be the use of asbestos in building materials, even though it was banned in 1977, resulting in later deaths. Another reason could simply be the rise in population. The higher the population, the higher the average number of cancer cases.