Vaughn Company is constructing a building. Construction began on February 1 and was completed on December 31. Expenditures were $2,088,000 on March 1, $1,236,000 on June 1, and $3,090,260 on December 31. Vaughn Company borrowed $1,083,960 on March 1 on a 5-year, 12% note to help finance construction of the building. In addition, the company had outstanding all year a 9%, 5-year, $2,493,000 note payable and an 10%, 4-year, $3,319,800 note payable. Compute the weighted-average interest rate used for interest capitalization purposes.