Assessing additional costs for 3 Ò100-year stormÓ
For three storms
Cost = $80,000 + $80,000 (SPPW i=0.06, n=13) + $80,000 (SPPW i=0.06, n=25) + $80,000 (SPPW i=0.06, n=37) + $4000(USPW i=0.06, n=50)
     
 = $80,000 + $80,000(0.4688) + $80,000(0.233) + $80,000(0.1158)+$4000(15.762)
        = $80,000 + $37,504 + $18,640  + $9,264 + $63,048
        = $208,488

negative effects = $90,000(SPPW i=0.06, n=13) + $90,000(SPPW i=0.06, n=25)
+ $90,000(SPPW i=0.06, n=37)             
             = $90,000(0.4688) + $90,000(0.233) + $90,000(0.1158)
                          = $42,192 + $20,970 +$10,422
            = $73,584
            = $208,488 + $73,584
              Ptb3storm = $282,072