How to enter document dimensions that are fractions?

Hello,

I need to create a document that is 36" x 11'-1-3/4" (thirty six inches by eleven foot one and three fourths). How do I enter this into Illustrator in a way that the program will understand? The 36" is fine, it's that 11'+ height that I'm struggling with. 

Do I write it as 11.175' ? (check here for how I got that decimal). Should I put 121.75" ? Or am I completely off the mark?

Thanks in advance!