Problem 5. A study was conducted on 70 school-aged children for the presence of respiratory tract infection. The subjects were evaluated by a doctor during four visits with a 3 month interval between consecutive visits. The data contains information on children's gender, baseline age, baseline BMI, and a presence of xerophthalmia. Use the SAS code and output to answer the following questions: (a) Specify the fitted model. Give estimates of all parameters. What is the name of this model? Is the model appropriate? (b) Identify significant predictors and interpret their estimated coefficients. (c) Predict the probability of a respiratory infection for a 12-year old girl with a BMI of 14.6, and with symptoms of xerophthalmia at the third visit.