In: Statistics and Probability
A two-by-two contingency table contains summaries obtained from n = 500 patients. Two binary variables, X and Y were processed, where X takes values ”Smoker” or ”Non-Smoker” and Y identifies blood pressure as ”High” or ”Normal”. The summaries are presented below.
High Normal Row Sum
Smokers 50 50 100
NonSmokers 150 250 400
Column Sum 200 300 500
1. Estimate expected counts and show them in the table similar to observed frequencies.
2. Evaluate the χ 2 -test statistic for independence between X and Y .
3. At significance level α = 0.05, do you have sufficient evidence that smoking and blood pressure may be related (dependent) variables? Show critical value and formulate rejection rule.