You are in desperate need of cash and turn to your uncle, who has offered to lend you some money. You decide to borrow $1,390 and agree to pay back $1,580 in two years. (a1) What annual interest rate is your uncle charging you? (if you solve this problem with algebra round Intermediate calculations to 4 decimal places, in all cases round your final answer to two decimal places, e.g. 8.72%) Rate of interest charged by uncle