In the article “Risk Factors Associated With Ischemic Stroke in Japanese Patients With Nonvalvular Atrial Fibrillation” published in JAMA Network Open (Okumura, 2020), the authors reported the results of a study on the risk factors that are associated with ischemic stroke in Japanese patients having nonvalvular atrial fibrillation.

The results of a proportional hazards model the authors fit are shown in Table 13.16.

Use the information in Table 13.16 to answer the following questions.

(a) Compute the value of the estimated coefficient for the variable Hypertension in the proportional hazards model.

(b) Compute the value of the estimated coefficient for the variable Body Mass Index in the proportional hazards model.

(c) Compute the value of the estimated coefficient for the variable Previous Stroke in the proportional hazards model.

(d) If the estimated standard error of the coefficient for the variable Previous Stroke is ???????? = 0.140, compute a 95% confidence interval for the risk ratio associated with Previous Stroke when all of the other variables are held fixed.