Carmen$$s Beauty Salon has estimated monthly financing requirements for the next six months as follows:

January $ $8,500$ April $ $8,500$

February $2,500$ May $9,500$

March $3,500$ June $4,500$

Short$-$term financing will be utilized for the next six months. Projected annual interest rates are:

January $9\mathrm{.}0\%$ April $16\mathrm{.}0\%$

February $10\mathrm{.}0\%$ May $12\mathrm{.}0\%$

March $13\mathrm{.}0\%$ June $12\mathrm{.}0\%$

What long$-$term interest rate would represent a break$-$even point between using short$-$term financing and long$-$term financing?