Hydrochloric Acid Leaching Study of Rare Earth Elements from Moroccan Phosphate

Table 6

Estimated values of coefficients for response Y.

Coefficient	Value	F. inflation	Ecart-Type	t. exp.	Significance %
b0	3.1648		0.1745858	18.13	<0.01
b1	2.7398	1.41	0.19519286	14.04	<0.01
b2	0.8526	1.13	0.16904198	5.04	0.395
b3	−0.3290	1.41	0.19519286	−1.69	15.3
b4	−5.2174	1.23	0.2618787	−19.92	<0.01
b5	1.5116	1.13	0.16904198	8.94	0.0291

t. exp indicates the experimental value of the student rapport calculated as follows: t. exp = value/Ecart-Type. Statistically significant at the level <99.99%. Statistically significant at the level 99%.