(17 points) Data from a study of abortion rates in the US in 1996 show that 14 states in the Midwest/Northeast had
low rates (less than or equal to 20 abortions per 1000 women) while 9 states had high rates (greater than 20 abortions per 1000 women). It also found that 17 states in the South/West had low rates while 11 had high rates. (Note that DC is included among the states.)
(4 points) Put these data into a 2 x 2 contingency table that classifies states by abortion rate (high vs. low) and region (Midwest/Northeast vs. South/West). Be sure to include the marginal frequencies.
(4 points) Estimate and interpret the odds ratio for having a high abortion rate, comparing Midwest/Northeast states to South/West states.
(5 points) Construct and interpret a 95% confidence interval for the odds ratio.
(4 points) Based on parts (b) and (c), would you reject the null hypothesis that H0: OR = 1 in favor of H1: OR ≠ 1 at the 5% significance level? (Do NOT perform a 7-step hypothesis test - use the confidence interval to justify your response.)