As there are 36 frames try the same shot at 800, 1250, 1600 and 3200. This still gives you 9 different shots and will tell you a lot about the best speed for you and maybe more importantly for your subject.
One cassette, nine shots and you might know all you need for every future shoot with D3200.
The different speeds call for different development times, so this approach won't work.
For general work, I shoot D3200 at 1000 to 1600 and develop for the time specified for 3200. It gives good results.