Hi Vicki,
The best way to do this is to have the data for each of those questions be in a repeating field. Then you could use the functions in InfoPath such as min(), max(), sum(), etc. to do your calculations.
If you're constrained to your current data source/schema, you'll need lots of rules and maybe a few temp variables to accomplish what you want. I would recommend the repeating approach since that will make things neater for you.