I was offered a job and initially was told the hourly rate would be $21. I was reviewing the paperwork to sign and the rate says $20. Would it be appropriate to say something?

I had three job prospects and accepted this position because it paid $21 being a dollar over the other two jobs. When I was offered the positions, the woman offered $21. Today I received the paperwork from HR that I would have to sign and return and it states the pay would be $20. Would it be appropriate to voice this?