Consider these facts: David and Karen want to buy a house for $$350,000$ and they have $20\%$ to pay down plus all required closing costs and fees. They apply for a loan from Bank of Oklahoma $($BOK$)$ in the amount of $$280,000.$ The loan is approved for $30$ years at $3\mathrm{.}75\%.$

a$.$ What is the loan payment amount?

b$.$ If BOK sells the loan to Wells Fargo on the same day the loan is originated at a yield to Wells$-$Fargo of $3\mathrm{.}30\%,$ what will Wells$-$Fargo have to pay BOK for the loan?

c$.$ What is BOK$$s gross profit on this sale transaction to Wells$-$Fargo?