Ch-11-pg-28-past exam sum. Qi) d) to compute the CI of mean difference, used the pivotal quantity of "two normal means. with unknown variance. AND Qii) b) to compute CI of mean difference, used pivotal quantity of "paired data" Why two diffrent methods? And is there any rule to use such alternative?
Both compare means - but the paired data should be used where the samples are not independent - they belong to the same individuals eg before and after situations.
Thanks. Then how to identify the data whether paired or not? Is it given in the question or by checking correlation?
It's usually clear from the question, eg the two samples are from the same individuals before and after a training programme...
How do we know in the ii part that it is paired? On reading both the subparts appear to be the same,ie, in both the inspectors go to similar houses..
