Answer A is $ 214,400, I need help with B.

On March 1, Nash Co. began construction of a small building. The following expenditures were incurred for construction: The building was completed and occupied on July 1. To help pay for construction $213,000 was borrowed on March 1 on a 12%, three-year note payable. The only other debt outstanding during the year was a $2,056,000,10% note issued two years ago. (a) Calculate the weighted-average accumulated expenditures. The weighted-average accumulated expenditures $ (b) Calculate avoidable interest. Avoidable interest $