Please explain the following statistics to me. The difference corresponded to an estimated unweighted RR of 1.28 (95% CI=1.04-1.57; P=.02 ) and an estimated weighted RR of 1.36 (95% CI= 1.07-1.73; P=0.1). The stratified log rank test with weighting of end points for the first 2 years, when applied to the 286 closed lung cancer cases, had a chi-squared value of 4.62 with 1 degree of freedom, corresponding to P=.03.