. 2021 Oct 5;11:19781. doi: 10.1038/s41598-021-99202-2

Table 2B.

Stepwise regression analysis in Experiment 2.

Experiment 2
Step 1: regression of Volume on pH (saving residuals to Res1)
Model: Volume = A + B * pH
Condition	R²		Coeff. value	Std. Error	95% confidence interval
Condition	R²		Coeff. value	Std. Error	Lower	Upper
3.75% Lugol	0.899	A	44.556	1.609	41.35	47.76
3.75% Lugol	0.899	B	8.485	0.317	7.85	9.12
3.75% B-Lugol	0.570	A	24.33	6.12	12.19	36.47
3.75% B-Lugol	0.570	B	10.610	0.892	8.84	12.38

Step 2: regression of Res1 on Osm
Model: Res1 = A + B * Osm
Condition	R²		Coeff. value	Std. Error	95% confidence interval
Condition	R²		Coeff. value	Std. Error	Lower	Upper
3.75% Lugol	0.010	A	3.55	7.29	− 11.16	18.26
3.75% Lugol	0.010	B	− 0.02	0.024	− 0.064	0.033
3.75% B-Lugol	0.110	A	− 15.87	5.38	− 26.64	− 5.09
3.75% B-Lugol	0.110	B	0.03	0.01	0.008	0.046

For description of the procedure: see Table 2A. Note that the intercepts (A) and slope coefficients (B) of the volume—pH relation show overlapping confidence intervals with those in the different conditions in Experiment 1, indicating that, even in B-Lugol a similar effect of pH on volume is present, but hardly any volume change is observed because the pH is almost constant.