Are there more women than men?

You are right about the ratios, it is mostly 1 to 1 on all societies. but this ratio is only true when considering men and women of same age. since the men usually in all societies marry younger women, the ratio becomes more women to men. There are other reasons that would make the ratio even higher. but any way, this not the reason why we are allowed up to 4 wives in Islam. Educate yourself properly.