The tests of normality (for all the Rf values) since the data is more than 30 (large sample) using Kolmogorov-smimov test the sig. value is 0.000 it is less than the probe value = 0.05. So it is non-parametric data.

Table 16: The tests of normality (for all the Rf values) since the data is more than 30 (large sample) using Kolmogorov-smimov test the sig. value is 0.000 it is less than the probe value = 0.05. So it is non-parametric data.

Tests of Normality
	Kolmogorov-Smirnova			Shapiro-Wilk
	Statistic	Df	Sig.	Statistic	df	Sig.
Data	0.263	187	0.000	0.726	187	0.000
a. Lilliefors Significance Correction