利息資本化 - 會計

During 2007, Tiger Building Company engaged Reese, Inc. to construct vraious
assets at a total cost of $8,400,000. Tiger made the following payments to
Reese during 2007:

Date Payment

June 1,2007 $6,000,000
August 31,2007 5,400,000
October 31,2007 1,800,000

The company had the following debt outstanding at December 31,2007:

A. 10%, 5-year note to finance construction of various assets, deted
January 1,2007, with interest payable annually on January 1: $3,600,000

B. 12%, ten-year bonds issued at par on December 31,2001, with interest
payable annually on December 31: $4,000,000

C. 9%, 3-year note payable, dated January 1,2006, with interest payable
annually on January 1: $2,000,000

我想請問這一題的資本化金額
解答是
累積支出平均數= $6,000,000* 3/12 + $11,400,000* 2/12 + $13,200,000* 2/12
= $5,600,000

專案:$3,600,000* 10% = $360,000
合計$580,000
其他:($5,600,000-3,600,000)* 11% = $220,000

再與認列利息($360,000 + 480,000 + 180,000)=$1,020,000 取小 ---$580,000

我的問題是
專案借款在 2007/1/1 就已經存在，1~5月並未使用專案借款，在算資本化金額時，
為什麼不是 $3,600,000* 7/12* 10% =$210,000 呢?
還有認列利息為什麼不是 $210,000 + 480,000* 7/12 + 180,000* 7/12 =595,000 呢?




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