multivariate statistics
| x1 | x2 | x3 | x4 |
| 8 | 98 | 12 | 8 |
| 7 | 107 | 9 | 5 |
| 7 | 103 | 5 | 6 |
| 10 | 88 | 8 | 15 |
| 6 | 91 | 8 | 10 |
| 8 | 90 | 12 | 12 |
| 9 | 84 | 12 | 15 |
| 5 | 72 | 21 | 14 |
| 7 | 82 | 11 | 11 |
| 8 | 64 | 13 | 9 |
| 6 | 71 | 10 | 3 |
| 6 | 91 | 12 | 7 |
| 7 | 72 | 18 | 10 |
| 10 | 70 | 11 | 7 |
| 10 | 72 | 8 | 10 |
| 9 | 77 | 9 | 10 |
| 8 | 76 | 7 | 7 |
| 8 | 71 | 16 | 4 |
| 9 | 67 | 13 | 2 |
| 9 | 69 | 9 | 5 |
| 10 | 62 | 14 | 4 |
| 9 | 88 | 7 | 6 |
| 8 | 80 | 13 | 11 |
| 5 | 30 | 5 | 2 |
| 6 | 83 | 10 | 23 |
| 8 | 84 | 7 | 6 |
| 6 | 78 | 11 | 11 |
| 8 | 79 | 7 | 10 |
| 6 | 62 | 9 | 8 |
| 10 | 37 | 7 | 2 |
| 8 | 71 | 10 | 7 |
| 7 | 52 | 12 | 8 |
| 5 | 48 | 8 | 4 |
| 6 | 75 | 10 | 24 |
| 10 | 35 | 6 | 9 |
| 8 | 85 | 9 | 10 |
| 5 | 86 | 6 | 12 |
| 5 | 86 | 13 | 18 |
| 7 | 79 | 9 | 25 |
| 7 | 79 | 8 | 6 |
| 6 | 68 | 11 | 14 |
| 8 | 40 | 6 | 5 |