Table 5 Independent samples t -test –... | Emerald Publishing

Table 5

Independent samples t-test – Lean index per Green aspect

Lean index	ISO 14001			ISO 50001			Green
Lean index	Statistic	df	p	Statistic	df	p	Statistic	df	p
Student’s t	−3.80	143	<0.001	−3.57	143	<0.001	−4.18	143	<0.001
Welch’s t	−3.35	49.6	<0.001	−6.61	8.71	<0.001	−4.19	136	<0.001
Mann–Whitney U	1,193		<0.001	89.5		<0.001	1,619		<0.001

Lean index	ISO 14001			ISO 50001			Green
Lean index	Statistic	df	p	Statistic	df	p	Statistic	df	p
Student’s t	−3.80	143	<0.001	−3.57	143	<0.001	−4.18	143	<0.001
Welch’s t	−3.35	49.6	<0.001	−6.61	8.71	<0.001	−4.19	136	<0.001
Mann–Whitney U	1,193		<0.001	89.5		<0.001	1,619		<0.001

Lean index	Material			Energy			Water
Lean index	Statistic	df	p	Statistic	df	p	Statistic	df	p
Student’s t	−2.02	143	0.023	−3.91	143	<0.001	−2.67	143	0.004
Welch’s t	−1.91	90.4	0.029	−3.46	71.1	<0.001	−2.15	21.1	0.022
Mann–Whitney U	1884		0.014	1,478		<0.001	732		0.003

Lean index	Material			Energy			Water
Lean index	Statistic	df	p	Statistic	df	p	Statistic	df	p
Student’s t	−2.02	143	0.023	−3.91	143	<0.001	−2.67	143	0.004
Welch’s t	−1.91	90.4	0.029	−3.46	71.1	<0.001	−2.15	21.1	0.022
Mann–Whitney U	1884		0.014	1,478		<0.001	732		0.003

Note(s): H_a 0 < 1

Source(s): The authors