Relation between n, p, q, and sigma

[ideaessence]

I know the value of n and p. I am looking for the standard deviation and mean based on those values. I gather that the forumla for sigma, the standard deviation, is:

sigma = square root of n*p*q

I do not know the value of q.

How can I find sigma? Do I need to find q first? If so, how do I find q if I only know n and p?

Thanks.

 

[galactus]

q is just 1-p