please explain why the first 3 expenditures are multiple by 9/12 then fourth and third ones are multiply by different number and also where does the 119380 come from? thank you

On January 2,2020, Concord Corporation began construction of a new citrus processing plant. The automated plant was finished and ready for use on September 30, 2021. Expenditures for the construction were as follows: January 2, 2020 $593000 September 1, 2020 1802400 December 31, 2020 1802400 March 31, 2021 1802400 September 30, 2021 1192000 Concord Corporation borrowed $3230000 on a construction loan at 10% interest on January 2, 2020. This loan was outstanding during the construction period. The company also had $12720000 in 7% bonds outstanding in 2020 and 2021. What were the weighted average accumulated expenditures for 2021 by the end of the construction period? $5941485 $4139085 $901200 $4317180 $5941485 $4139085 $901200 $4317180 eTextbook and Media Solution Assistance Used 1($593000+ $1802400 + $1802400+ $119380) * 9/12]+($1802400 x 6/12) + ($11920000/12) - $4139085. ($593000* 12/12) + ($1802400 4/12) + ($18024000/12) - 51192000. Attempts: 1 of 1 used