# Mean and Variance

• Jan 15th 2012, 04:05 PM
Marmy
Mean and Variance
Hi everybody,

I encountered this to me very confusing problem in the context of confidence intervals and pivotal quantities.

How can I compute the mean and the variance (marked yellow) with this information below...

Many thanks once more!
• Jan 16th 2012, 02:50 PM
Moo
Re: Mean and Variance
Hello,

The only random stuff in $\hat\theta_2$ is $x_i$. So if you treat everything else as a constant, it's pretty easy to compute the mean and the variance !
After that, it's just a matter of computing double sums :)

Let's try it !
• Jan 17th 2012, 07:25 AM
Marmy
Re: Mean and Variance
Thanks, I think I found out now!