Statistical Analysis of a Weibull Extension with Bathtub-Shaped Failure Rate Function

Table 6

Estimation results using data in Wu et al. [11].

Parameter	MLE	MOM	MMOM	IMOM	MIM
	0.2893	0.3102	0.3005	0.2806	0.2741
	100.4048	189.7327	139.5206	78.9727	66.6931
Approach		95% confidence interval for			Length
Chen’s (Wu’s exact )		(0.1986, 0.3697)			0.1771
Wu’s exact ()		(0.2106, 0.3299)			0.1193
Wu’s exact ()		(0.2066, 0.3261)			0.1195
Wu’s approximated ()		(0.2122, 0.3220)			0.1098
MOM pivot		(0.2304, 0.3640)			0.1336
MIM pivot		(0.2237, 0.3260)			0.1023