Xm | mean | standard deviation | minimum | maximum |
X1 | 1.61 | 0.686 | 1 | 4 |
X2 | 1.98 | 0.690 | 1 | 4 |
X3 | 2.17 | 0.758 | 1 | 4 |
X4 | 2.36 | 0.828 | 1 | 4 |