A coin was tossed 20 times, with 16 tails and 4 heads. Let \(\displaystyle Y\) be the number of heads thrown. How would I test this?

Guessing you'd start off with something like:

\(\displaystyle Y - Bi(20,p)\)

\(\displaystyle H_0: p=0.5\)

\(\displaystyle H_A: p \neq0.5\)

Not sure how to procede from here, if I was testing a Normal Distribution I'd calculate a p-vaule, just not sure how to do it for the Binomial.

Thanks in advance