Which statistics test do I use?

You can't frame your hypotheses that way. You need H0: p = 0.5 and H1: p > 0.5 or however you frame them you cant have H1: [something] equals [something else]. In this case, it looks like a 2-sided 95% test rejects H0: p = 0.5 handily (you are supposed to pick alpha before you run your test). Use two-sided test: H0: p= 0.5 vs H1: p <> 0.5 and your test statistic has 0.5 in it, not 0.45 but you will still reject at 0.05 easily.