Question

Medical researchers are concerned about the association between maternal smoking habits and the need for caesarian section during birth. Suppose the researchers gather 423 expecting mothers in their third trimester and follow them through pregnancy to examine the incidence of caesarian. Suppose out of the 102 mothers that reported smoking cigarettes at least once during pregnancy, 59 of them were referenced to have needed caesarian intervention during delivery, while 73 of the mothers with no smoking history reportedly needed the procedure.

A) Calculate the risk difference for caesarian among smokers during pregnancy versus non-smokers.

B) Construct a 95% confidence interval for your estimate.

C) Carry out a formal test to determine if the difference in risk due to the exposure is statistically significant at the alpha level of 0.05.

D) Interpret your results from B and C to determine if there is a relationship between maternal smoking habits and risk for caesarian.

Choose the most appropriate option

		Option 1 a. 0.555 b. (0.78, 0.99) c. Ho: p1=p2; Ha: p1≠p2; Z stat=7.5Pvalue <0.0001 d. Accept the Ho that there is a difference in caesarian due to maternal smoking habits. The confidence interval suggests that the risk difference is actually much lower among mothers that reported smoking during pregnancy compared to those that did not.
		option 2    a. 0.351   b. (0.24, 0.46)                c. Ho: p1=p2; Ha: p1≠p2; Z stat=6.5Pvalue <0.0001 d. Reject the Ho that there is no difference in caesarian due to maternal smoking habits. The confidence interval suggests that the risk difference is actually much greater among mothers that reported smoking during pregnancy compared to those that did not.
		option 3 a. 1.356 b. (0.11, 0.50) c. Ho: p1≠p2; Ha: p1=p2; Z stat=6.0Pvalue >0.0001 Reject the Ho that there is a difference in caesarian due to maternal smoking habits. The confidence interval suggests that the risk difference is actually much less among mothers that reported smoking during pregnancy compared to those that did not.

Answer 1