A study examining the health risks of smoking measured the cholesterol levels of people who had smoked for at least 25 years and people of similar ages who had smoked for no more than 5 years and then stopped.
n=15 for both lists of data.
Smokers for 25+ yrs: 225, 258, 250, 225, 213, 232, 216, 216, 178, 287, 200, 211, 216, 200, 256
Ex-smokers: 188, 174, 213, 134, 217, 217, 242, 192, 238, 200, 210, 160, 175, 249, 250
Enter your data into your calculator.
1. Stat, Edit, L1: Smokers cholesterol levels
2. Stat, Edit, L2: Ex-smokers cholesterol levels
3. Display stacked boxplots for the two data sets:
Turn Statplot #1 ON (2nd, y=, Statplot#1), choose the modified boxplot (next to the histogram),
Xlist: L1 (2nd, 1), Freq=1
Turn Statplot #2 ON (Statplot #2, enter), choose the modified boxplot (next to the histogram),
change Xlist: L2 (2nd, 2), Freq=1
4. Zoom 9 to display the stacked boxplots. Remember that the smokers data is displayed on top,
Remember: Smokers are the top boxplot and Ex-smokers are the bottom boxplot.
Compare the two boxplots, noting the location of the quartiles. Rotate your calculator to the side if this helps you see the quartiles for comparison.
Using the quartiles, what percent of the Ex-smokers cholesterol levels were lower than 100% of the smokers cholesterol levels?