656                                                    20

   :     $0.   -
,      Widget    $100,  $80.  -
         .     
    $89,44,   ,      
   ,       .

-, ,     , ..    0.
         :

$111,80      = $15,72

$100-

$89,44       = $0

  (20.5)  (20.6) ,    h  0.7030
[($15,72-$0)/($111,80- $89,44)]      $60,41 [(0,7030  $89,44-
 $0)/1,0408].   (20.7),      -
 t = 0.   $9,89 (0,7030  $100 - $60,41).

    .     -
     12- .  -
  ,      Widget      -
     .  ,   . 20.5() -
  ,        .   
  ,       .  ,   
        5  13  .

20..2    

     .    ?  
    ,       .
     Widget    ,   
   - $100,   -     .
     :

^^- $125        , = $0
$100<^^

^^^ $80         ^ = $20

 (20.5)       0,4444 [($0 - $20)/
/($125 - $80)].    ,    .  ,
        .

 (20.6) ,    - $51,28.    -
 ,      - $55,55.    
,    ,      (. . -
        -
 ).

   ,     0,4444
 Widget    (..    )
$51,28.      $44,44,     
$51,28,       $6,84 ($51,28 - $44,44).
 ,       .

   ,      (20.7): $6,84 [0,4444 $ 100- (-$51,28)],
 h = 0,4444, = -$51,28  Ps= $100.  ,  (20.5), (20.6)  (20.7)
       ,     -