. 2020 Nov 4;5(45):29199–29208. doi: 10.1021/acsomega.0c03967

Table 5. Model Summary Statistics for the Standard Deviation of the Ash Content of −3 + 1 mm Lignite.

type	standard deviation	R²	adjusted R²	predicted R²	PRESS
linear	1.76	0.0617	–0.0947	–0.3060	103.31
2FI	1.92	0.1652	–0.2986	–1.0244	160.14
quadratic	0.43	0.9675	0.9350	0.8206	14.19	suggested
cubic	0.17	0.9979	0.9902	0.9574	3.37	aliased