8. A study was conducted to assess the association between exposure to environmental tobacco smoke (ETS) and lung cancer. 292 nonsmoking lung cancer cases and 1,238 nonsmoking controls were inter- viewed about exposure to ETS. Let ETS= 1 if a person has been exposed to ETS and 0 otherwise, cancer=1 if a person has lung cancer and 0 otherwise. The following shows the results of the data analysis: tabulate cancer ETS [fweight = frequest], chi2 expected Key frequency expected frequency ETS cancer Total 0 391 847 1, 238 422.4 815.6 1, 238.0 1 131 161 292 99 . 6 192 .4 292 . 0 Total 522 1, 008 1, 530 522.0 1, 008.0 1, 530.0 Pearson chi2 (1) = 18.5374 Pr = 0.000 (a) (4pts) Can you estimate the risk (proportion) of lung cancer with ETS exposure? If yes, what is the estimate? (b) (4pts) Can you estimate the odds of lung cancer with ETS exposure? If yes, what is the estimate? (c) (4pts) Test the null hypothesis that lung cancer is independent of ETS exposure at the a = 0.05 level. Give the test statistic, d.f., critical value and test results