1. Suppose that the following data are obtained from a hypothetical study on gender and congenital heart disease (CHD) among individuals with down syndrome. For answering the following questions you may use the package DescTools.

Gender CHD No CHD Total

Female 140 170 310

Male 120 270 390

700

(a) Estimate the odds ratio of the CHD from female to male.

(b) Obtain the 95% confidence interval for the odds ratio.

(c) Based on the confidence interval calculated in the previous question test the hypothesis of independence between the two variables. [Do not forget to write the null and alternative hypotheses in terms of the odds ratio].

(d) What is the estimated relative risk of CHD from female to male among the down syndrome subjects, and interpret the result.