It sure is possible to run multiple versions of Yellowfin on the same computer! :-)
Personally I have more than 10 different builds installed at the moment.
You basically just need to make sure that when you install them, you install them onto different port numbers.
Yellowfin 7.1 - Run on port 8071
Yellowfin 7.2 - Run on port 8072
This should work for you.
Side note - glad to heart people are keen to check out 7.2!