Table 3.
Coefficient estimation in terms of coded factors.
| Factor | Coefficient Estimate | df | Standard Error | 95% CI Low | 95% CI High | VIF |
|---|---|---|---|---|---|---|
| Intercept | 36.59 | 1 | 0.0141 | 36.55 | 36.62 | |
| A: Amplitude | 3.08 | 1 | 0.0104 | 3.06 | 3.11 | 1.0000 |
| B: Solute to solvent ratio | 0.4920 | 1 | 0.0104 | 0.4673 | 0.5167 | 1.0000 |
| C: pH | 0.1120 | 1 | 0.0104 | 0.0873 | 0.1367 | 1.0000 |
| AB | 0.0050 | 1 | 0.0117 | −0.0226 | 0.0326 | 1.0000 |
| AC | 0.0050 | 1 | 0.0117 | −0.0226 | 0.0326 | 1.0000 |
| BC | −0.0250 | 1 | 0.0117 | −0.0526 | 0.0026 | 1.0000 |
| A2 | −0.3726 | 1 | 0.0202 | −0.4203 | −0.3250 | 1.54 |
| B2 | 0.1124 | 1 | 0.0202 | 0.0647 | 0.1600 | 1.54 |
| C2 | −1.71 | 1 | 0.0202 | −1.76 | −1.66 | 1.54 |
df = degree of freedom; CI = confidence interval; VIF = variance inflation factor.