(a) 15:45 = 15/45=1/3=1:3
40 : 120 = 40/120=1/3=1:3
Since 15 : 45 = 40 : 120
Therefore, 15, 45, 40, 120 are in proportion.

(b) 33 : 121 = 33/121=3/11=3:11
9 : 96 = 9/96=3/32=3:11
Since 33 : 121 ≠ 9 : 96
Therefore, 33, 121, 9, 96 are not in proportion.

(c) 24 : 28 = 24/28 = 6/7 =6:7
36 : 48 = 36/48 = 3/4=3:4
Since 24 : 28 ≠ 36 : 48
Therefore, 24, 28, 36, 48 are not in proportion.

(d) 32 : 48 = 32/48 = 2/3 = 2 : 3
70 : 210 = 70/120 = 1/3 = 1:3
Since 32 : 48 ≠ 70 : 210
Therefore, 32, 48, 70, 210 are not in proportion.

(e) 4 : 6 = 4/6= 2/3- 2:3
8 : 12 = 8/12 = 2/3 = 2:3
Since 4 : 6 = 8 : 12
Therefore, 4, 6, 8, 12 are in proportion.

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