416 



CHARTS, GRAPHS, TABLES, AND COMPUTATIONS 



370 

 350 

 330 

 310 

 290 

 2 70 



380 

 360 

 340 

 320 

 300 

 280 



99.5 99.99 



0.1 I 5 20 40 60 80 95 99 99.9 0.1 I 5 20 4060 80 95 99 99.9 



P OF N, >0RDINATE VALUE 



Figure 9.16. Cumulative probability distribution of Ng, San Antonio, Tex. 



