668                                                    20

           
   (  ).    . 20.3 () 
()           
 0.     . 20.6  20.8 ,     
    .    , 
         .

20.8.1       

              -
   .    . 20.9  ,    
   ,      
.     ,      
   ,     .

  (20.9)     ,  -
       :

^^^IF-^-                            (20.16)

 ,     ,   
        .
     ,     -
        .

,           -
 $40.         -
  $36  50%.   ,       5% -
   ,    , -
 $2,26.   5%       ,  -
     $39,50[$40/(0'05'10-25)].   ^ = $2,26,
/^ = $39,50  , = $36,    (20.16)  
  .   $5,76 ($2,26 + $39,50  $36).

    ,   -  
   (  (20.10))  ^  
(20.16).         -
    :

^=-^<-^-^-^.                     (20.17)

 d,  d^    (20.11)  (20.12).

   d, = -0,25  d^ = -0,50;   N(-d,) = N(0,25) =
= 0,5987  N(-d,) = '(0,50) = 0,6916.    (20.17)  -
    :

 =[  $40   0,6915 -($360,5987)=

        0,050,25

\           1

= $27,31 - $21,55 = $5,76.
   ,      (20.16).