19 



Therefore 



30.71 



= 7.69 





[23] 



10 + 0.03 + 0.59 + 0.( 



= 0.52 



and 



when X. is used. 



V^> Q^521_ ^ -^ 4^ fron, Equation [22] 



0.05 (7.36) ^ 



As a first approximation, assume c = 5. The value k{t) from the "<" table at a 0.90 

 probability level and four degrees of freedom is 2.13 



v^>1.4 • 2.13 



As a second approximation, assume c = 6 



VT= 1.4 • 2.02 

 Therefore c = 7, indicating that measurements would have to be made over a period of 7 yr to 

 establish a distribution pattern which would be valid at a probability level of 0.90 such that 

 Equation [19] is satisfied, providing that no year-to-year bias exists in the data. 



