“…There are two ways to express interval grey numbers, one being the conventional data range expression (see the data on the left of each column in the table) and the other being the combination expression of a kernel and the degree of greyness (see the data on the right of each column in the table). [15,20] 17.5 0.25 [9,10] 9.5 0.08 [4,6] 5.0 0.33 [22,30] 26.0 0.13 [10,15] 12.5 0.17 S 2 [20,22] 21.0 0.10 [12,14] 13.0 0.15 [4,7] 5.5 0.50 [30,35] 32.5 0.08 [25,32] 28.5 0.24 S 3 [16,30] 23.0 0.70 [11,13] 12.0 0.15 [5,8] 6.5 0.50 [40,50] 45.0 0.17 [18,28] 23.0 0.34 S 4 [25,30] 27.5 0.25 [13,18] 15.5 0.38 [7,9] 8.0 0.33 [60,65] 62.5 0.08 [20,35] 27.5 0.52 S 5 [22,24] 23.0 0.10 [10, 13] 11.5 0.23 [4,6] 5.0 0.33 [45,50] 47.5 0.08 …”