
Central Limit Theorem
What is the probability that after 80 rolls of a die, the total sum of the upturned faces will exceed 260?
So far I have (1  P(X1+...+X80  80(mean X1) <= 260)) / (std. dev.)(sqrt(80)).
Am I doing this correctly, and if so, how do I find the mean and std. deviation to put into the equation?

upturned faces=sum of the spots?
Then you want
$\displaystyle P(\sum_{i=1}^{80}X_i>260)$
I would put in a correct factor and approximate it with a normal...
$\displaystyle \approx P(\sum_{i=1}^{80}X_i>260.5)$
where the X's are iid from the distribution that puts 1/6 probability on {1,2,3,4,5,6}.