Consider a study in which people were recruited and followed for 40 years to determine their health problems. The researchers were interested in lung cancer so at the end of the study they counted the number of participants who had died from lung cancer, or currently had it, and those that did not. They also counted how many were non-smokers their whole life or had been smokers at some point in their lives. The number of non-smokers with lung cancer was 36 and the number of non-smokers with no sign of lung cancer was 815. The number of smokers with lung cancer was 26 and the number of smokers with no sign of lung cancer was 161.
To determine whether there appears to be a statistically significant relationship between smoking and risk of lung cancer we would conduct a χ² analysis. Based on the results of this analysis, which of the following is the most appropriate conclusion?

Question

Quizplus · Accepted Answer

The correct statistical test for examining the relationship between two categorical variables (smoking status and lung cancer occurrence) is the chi-square (χ^2) test. The choice indicating that smoking significantly elevates the risk of lung cancer with a p-value less than 0.05 (P < 0.05) suggests that the difference observed in lung cancer rates between smokers and non-smokers is statistically significant, meaning it is unlikely to have occurred by chance.

Consider a Study in Which People Were Recruited and Followed