Table 5.

Descriptive statistics of the subject-specific covariates in application.

	Vars	n	Mean	sd	Median	Trimmed	Mad	Min	Max	Range	Skew	Kurtosis	se
Year of study	$x_1$	100	1.18	0.39	1.00	1.10	0.00	1.00	2.00	1.00	1.64	0.70	0.04
ECTS	$x_2$	100	37.69	40.22	27.00	28.89	5.93	0.00	163.00	163.00	1.90	2.23	4.02
Grade point average	$x_3$	100	23.02	6.93	24.80	24.49	3.26	0.00	30.00	30.00	−2.36	5.17	0.69
Course attendance	$x_4$	100	87.37	13.34	90.00	89.53	13.34	40.00	100.00	60.00	−1.22	0.93	1.33
Daily study hours	$x_5$	100	3.73	1.62	4.00	3.64	1.48	0.25	8.00	7.75	0.48	0.05	0.16
Age	$x_7$	100	21.00	3.25	20.00	20.27	1.48	19.00	41.00	22.00	3.16	13.59	0.33