95% of confidence limit exist between -
Ans. is 'b' i.e., +- 2 SD 1 SD --> Coveres 68% of area (68% confidence limit) 2 SD --4 Coveres 95% of area (95% confidence limit) 3 SD --> Coveres 99.7% of area (99.7% confidence limit)
+- 1. S.D.
+-2 S.D.
+-3 S.D
+- 4 S.D.