如何在Excel中计算可变付款抵押贷款的加权平均寿命

我试图找出如何使用以下7%利率抵押贷款的现金流计算截至2016年6月30日的现值和加权平均寿命

对于沃尔玛，我尝试了利息支付/利率x原则，但没有奏效。如果有任何想法，我将不胜感激

Dates        Principal      Interest   Ending Balance
15-Apr-16    $-             $-           $10,000,000 
15-May-16    $50,000         $41,667     $9,950,000 
15-Jun-16    $50,000         $42,840     $9,900,000 
15-Jul-16    $50,000         $41,250     $9,850,000 
15-Aug-16    $50,000         $42,410     $9,800,000 
15-Sep-16    $50,000         $42,194     $9,750,000 
15-Oct-16    $50,000         $40,625     $9,700,000 
15-Nov-16    $50,000         $41,764     $9,650,000 
15-Dec-16    $50,000         $40,208     $9,600,000 
15-Jan-17    $50,000         $41,333     $9,550,000 
15-Feb-17    $50,000         $41,118     $9,500,000 
15-Mar-17    $50,000         $36,944     $9,450,000 
15-Apr-17    $50,000         $40,688     $9,400,000 
15-May-17    $50,000         $39,167     $9,350,000 
15-Jun-17    $50,000         $40,257     $9,300,000 
15-Jul-17    $50,000         $38,750     $9,250,000 
15-Aug-17    $50,000         $39,826     $9,200,000 
15-Sep-17    $50,000         $39,611     $9,150,000 
15-Oct-17    $50,000         $38,125     $9,100,000 
15-Nov-17    $50,000         $39,181     $9,050,000 
15-Dec-17    $50,000         $37,708     $9,000,000 
15-Jan-18    $50,000         $38,750     $8,950,000 
15-Feb-18    $50,000         $38,535     $8,900,000 
15-Mar-18    $50,000         $34,611     $8,850,000 
15-Apr-18    $50,000         $38,104     $8,800,000 
15-May-18    $50,000         $36,667     $8,750,000 
15-Jun-18    $50,000         $37,674     $8,700,000 
15-Jul-18    $50,000         $36,250     $8,650,000 
15-Aug-18    $50,000         $37,243     $8,600,000 
15-Sep-18    $50,000         $37,028     $8,550,000 
15-Oct-18    $50,000         $35,625     $8,500,000 
15-Nov-18    $50,000         $36,597     $8,450,000 
15-Dec-18    $50,000         $35,208     $8,400,000 
15-Jan-19    $1,000,000      $36,167     $7,400,000 
15-Feb-19    $1,250,000      $31,861     $6,150,000 
15-Mar-19    $1,250,000      $23,917     $4,900,000 
15-Apr-19    $400,000        $21,097     $4,500,000 
15-May-19    $2,000,000      $18,750     $2,500,000 
15-Jun-19    $2,500,000      $10,764     $- 

2016/6/30之前的截止日期，保留大于或等于2016/6/30的日期。（如上所述）

制作CF列，

=C3+D3

制作无年份栏，

=（B3-$B$3）/365

制作CF*no\u of\u year列，

=G3*F3

使用

XNPV

函数获取现值，

=XNPV（0.07，F3:F39，B3:B39）

通过

=SUM（H3:H39）/SUM（F3:F39）