Table 2.

One-way analysis of variance of surface roughness of all groups based on beverages and time

	Sum of squares	df	Mean square	F	P
Group 1 (control)
Between groups (combined)	0.064	3	0.021	162.962	0.01
Within groups	0.005	36	0
Total	0.069	39
Group 2
Between groups (combined)	11.738	3	3.913	34,033.78	0.01
Within groups	0.004	36	0
Total	11.742	39
Group 3
Between groups (combined)	16.59	3	5.53	27,534.32	0.01
Within groups	0.007	36	0
Total	16.597	39
Group 4
Between groups (combined)	32.628	3	10.876	8523.714	0.01
Within groups	0.046	36	0.001
Total	32.674	39

df: Degrees of freedom; F: F statistics; P: Probability value