696                                                    21

  $20 000 (5000  $4),    $5000.      -
     S   $5000,     -
  ,    ,     ,   -
         .5'.

()         
  S4  :

____  $20 000    _^

                                                            S

<

  5000 

()       :

  $20 000                      $20 000

                                                               S

<                  <

  5000    5000 

. 21.2.    

        $3,    $20 000  
,    $15 000 ($3  5000)   .  -
,    ?        ,
  S.      $15 000   .  
     5" $20 000,    $5000. , -
            $5000,   
       .

,       ,
: (1)        -
 ; (2)       ;

(3)        
.

21.3.2    

     ,    -
    .        -
   (,       ). 
     ,      -
 .    ,     , 
    ;    -
   (performance margin}.     -
  5  15%    .   
         4.

,       $5000   $4 
    $20 000 (5000  $4).  5%-  
        $1000 (0,05  $20 000). -