Please show your work on each calculation, I really need help in understanding the step-by-step process in this. Thank you.

Whispering Company is constructing a building. Construction began on February 1 and was completed on December 31. Expenditures were $4,680,000 on March 1, $3,120,000 on June 1, and $7,800,000 on December 31. Whispering Company borrowed $2,600,000 on March 1 on a 5-year, 10% note to help finance construction of the building. In addition, the company had outstanding all year a 12%, 5-year, $5,200,000 note payable and an 11%, 4-year, $9,100,000 note payable. Compute avoidable interest for Whispering Company. Use the weighted average interest rate for interest capitalization purposes. (Round "Weighted-average interest rate" to 4 decimal places, e.g. 0.2152 and final answer to O decimal places, e.g. 5,275.) Avoidable interest $ 289,536