\Need clear explaination

Bramble Corp. is constructing a building. Construction began on January 1 and was completed on December 31 . Expenditures were $6420000 on March 1, $5350000 on June 1, and $8150000 on December 31. Bramble Corp. borrowed $3240000 on January 1 on a 5-year, 11% note to help finance construction of the building. In addition, the company had outstanding all year a 9%,3-year, $6390000 note payable and an 10%,4-year, $12550000 note payable. What is the weighted-average interest rate used for interest capitalization purposes? eTextbook and Media Solution [($63900000.09)+($125500000.10)]($6390000+$12550000)=9.66%