Ask HN: Are forced gender distributions for hiring interns legal?

A hypothetical company offers an engineering internship program. This company's applicant pool has a ~80%/20% gender distribution (which is consistent with engineering student enrollment). However, this company's hired intern class consistently has a ~50%/50% gender distribution. Such a distribution cannot be achieved via random selection from the applicant pool, unless either the minority gender was much stronger than the majority gender, or the distribution was somehow "forced" during the hiring process. Is this legal?