556 



BELL SYSTEM TECHNICAL JOURNAL 



0.0018 

 0.0016 

 0.0014 

 0.0012 

 0.0010 

 0.0008 

 0.0006 

 0.0004 



CE 0.0002 'f 



0.1 0.2 0.3 0.4 0.5 0.6 0.7 

 STANDARD DEVIATION OF SUBGROUP LOADS CARRIED 



Fig. — 20 Effect of subgroup load variation on probability of loss — 36 graded trunks 



0.024 

 0.022 



< 



^ 0.018 

 o 



C 0.016 



o 



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 _i 



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a 



0.002 



0.2 0.4 0.6 0.8 1.0 1.2 



STANDARD DEVIATION OF SUBGROUP LOADS CARRIED 



Fig. 21 — Effect of subgroup load variation on probability of loss — 52 graded trunks. 



