Table 4.

Results of modified Weibull parameters.

Test data4,37–39	Distribution function	Weibull parameters			Error
		$b$	$\theta$	$N_{f_0}$	K–S test (%)	R-square
Data set 1	Step function	0.89	349,600,000	5,497,000	8	0.986
	Modified Weibull	0.62	344,000,000	9,050,000	6	0.999
Data set 2	Step function	0.90	132,806,849	4,384,680	10.2	0.967
	Modified Weibull	0.62	137,984,686	4,019,219	5.4	0.999
Data set 3	Step function	1	63,647,140	2,938,570	8.7	0.969
	Modified Weibull	0.7	65,883,507	2,160,990	5.2	0.999
Data set 4	Step function	0.58	32,506,615	1,479,600	11.6	0.963
	Modified Weibull	0.4	37,336,316	2,574,857	9.2	0.997
Data set 6	Step function	1.59	602,100	117,100	9.3	0.93
	Modified Weibull	0.86	592,300	79,200	5	1
Data set 8	Step function	0.85	169,100	61,130	16	0.976
	Modified Weibull	0.69	176,000	140,000	2	1
Data set 16	Step function	1.1	179,400	1647	10.2	0.980
	Modified Weibull	0.7	168,000	15,938	5.8	0.993