# Roll a Die question help please

• November 19th 2012, 12:46 PM
Nasc0
Roll a Die question help please
if i roll a die 600 times. whats the mean and standard deviation of the number of 3's that show?
• November 19th 2012, 01:19 PM
skeeter
Re: Roll a Die question help please
probability problems go in the statistics forum
• November 19th 2012, 01:30 PM
Plato
Re: Roll a Die question help please
Quote:

Originally Posted by Nasc0
if i roll a die 600 times. whats the mean and standard deviation of the number of 3's that show?

If $p$ is the probability of success and $N$ is the number of trials then the mean is $\mu=p\cdot N$ and $\sigma=\sqrt{Np(1-p)}$.