3. (15 pt) You may not use R's gim command for this question. Aflatoxin Bl was fed to lab animals at various doses. The dose in ppb (dose), number of test animals (total) and number with liver cancer (tumor) is recorded. The data is presented in the following table dose total tumor O 18 1 22 22 1 15 21 4 50 25 20 100 28 28 We are interested in building a model to predict the occurrence of liver cancer. (a) Fit a binomial regression model to the data using a logit link. (b) Construct the 95% CIs for the parameter estimates. (c) Perform a likelihood ratio test for the significance of the dose coefficient. (d) Estimate the probability of developing liver cancer when the dose is 30 ppb together with a 95% CI. (e) Refit the binomial regression model using a probit link. (f) Create a plot comparing the fitted probit model to the fitted logit model