Histologic stage is an ordinal categorical variable coded as 1-4 (higher values meaning more advanced progression of disease). Suppose this is initially modeled as a semi continuous variable in a Cox regression:

ln(h : ) = ln j45()l + 0.82-, where x1= histologic stage (1-4). The standard error of the slope for x1 is 0.12.

Part 1) Based on these results, what is the estimated hazard ratio of death for patient with a histologic stage of 4 compared with a histologic stage of 1?

A) 2.26

B) 6.78

C) 11.50

Part 2) Then what is the 95% CI for the hazard ratio.