Confidence interval question

[Bozeman]

Supposes you have a possibly biased coin. You flip it n times, getting m heads. What interval can you say it's probability of heads is in with 95% confidence? With 67% confidence?

Craig

[Henke]

If we can assume that n is large, then it should be:

p±1.96*sqrt(m(n-m)/n^3) for 95% confidence and

p±0.98*sqrt(m(n-m)/n^3) for 67% confidence