Your friend has two investment opportunities that she is considering and has asked for your advice regarding how she should proceed. One will have an $12\mathrm{.}0\%$ rate of return on an investment of $$510$; the other will have a $15\mathrm{.}0\%$ rate of return on an investment of $$730.$ She would like to take advantage of the higher$-$yielding investment but has only $$510$ available.

Required:

What is the maximum rate of interest that your friend should be willing to pay to borrow the $$220$ needed to take advantage of the higher yield?

Note: Do not round intermediate calculations. Round your answer to $2$ decimal places.