Stats is a science. It is a branch of mathematics.
That said, better to get a letter from someone who has taught a humanities coures: English, foreign language, philosophy, theology/religious studies, art history, architechture, music, film, communications, etc. Almost every school has some gen ed requirements such that you will have taken a few classes along those lines. We are looking for an assessment of your critical thinking skills, communication skills (written and verbal), ability to listen to and respect different points of view, to make a case in a group discussion for your point of view, and to work well in groups.