haha I just finished mine. had to write 2x peer reviews on issue proposals. I'm proud of myself for being able to understand the majority of what you just posted since I haven't taken spanish in 2 years xD
The bank will short the 6-month T-Bill for $97.728 and then go long 1.02105 (97.728/95.713) 1-year T-Bills at $95.713. This results in zero net cash flow to the bank today.
At t=0.5, the bank will have to pay back $100 from the counterparty it borrowed the T-Bills from. However this will be offset by the $100 it receives from the firm