Please answer a b c d e f ( or the most you can answer thank you! ) . It is a statistics question ( survival analysis ) .

Consider the following survival data: ti 1 2+ 3 4 5+ 6 21i 0 1 1 1 0 0 where to is the survival time, and the "+" sign denotes a right-censored observation. Consider a Cox regression model with a single explanatory factor Z1. a) Give the partial likelihood (Cox) formula for the sample of board. b) Find the derivative of the log-likelihood associated with the data. Calculate the maximum likelihood estimator of the Cox regression parameter. c) Find the Breslow estimator of the cumulative risk function. d) Estimate S (5) for an individual with Z1 = 1. e) Suppose we want to test the hypothesis HO: B1= 0. Calculate the statistic for the likelihood ratio test. What is your conclusion? f) Find an estimator of Fisher's information. Construct a 95% confidence interval of B1