Proportionality coefficient before and after treatment		Leven’s Test for Equality of Variances		t-test for Equality of Means
		F	Sig.	t		Sig. 2-taild	Mean Difference M(R)	Std. Error Difference SE	95% Confidence Interval of the Difference
		F	Sig.	t		Sig. 2-taild	Mean Difference M(R)	Std. Error Difference SE	Lower	Upper
k_p	Equal variances	8.642	0.003	1.089	394	0.277	0.01096	0.01006	−0.00882	0.03074
k_p	Unequal variances			1.104	387.411	0.270	0.01096	0.00993	−0.00856	0.03048
k_o	Equal variances	0.305	0.581	−1.172	394	0.242	−0.04426	0.03778	−0.11853	0.03001
k_o	Unequal variances			−1.171	388.502	0.242	−0.04426	0.03779	−0.11857	0.03004