Use the file winter.dat for this exercise. The data were first discussed in Exercise 19 of Chapter 3.

1. Test the null hypothesis that class is not associated with breakaga. In the context of Section 10.1, what type of sampling was done?

2. Now construct a 2 × 2 contingency table for the variables breakaga and work.

Use the sampling weights to estimate the probabilities pij for each cell.

3. Calculate the odds ratio using the Ṕij from (b). How this compare with odds ratio does calculated using the observed counts (and ignoring the sampling weights)?

4. Estimate θ = p11p22 − p21p12 using the Ṕij you calculated in (b).

5. Test the null hypothesis H0 : θ = 0.