upturned faces=sum of the spots?
Then you want
I would put in a correct factor and approximate it with a normal...
where the X's are iid from the distribution that puts 1/6 probability on {1,2,3,4,5,6}.
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?