SURVIVAL ANALYSIS Techniques for Censored and Truncated Data Second Edition John P. Klein Medical College of Wisconsin Melvin L. Moeschberger The Ohio State University Medical Center

11.2.) In section 1.14 a study of the times to weaning of breast-fed new- borns was presented. This data is available on our web site. Categorical variables which could explain the difference in weaning times are the mother's race (white, black, other), smoking status, and an indicator of whether the mother was in poverty. Continuous variables which could explain outcome are the mother's age at the child's birth, mother's years of education, and the child's year of birth. Using a Cox model with appropriate terms for the mother's race, smoking status, and poverty indicator, determine if each of the three continuous covariates would enter the model as a linear function.

answer this question using the "bfeed" data set in R. here is the link explaining the variables in the data set: https://cran.r-project.org/web/packages/KMsurv/KMsurv.pdf