Question

Question
Determine which set of ratios forms a proportion.

This question requires you to show your work.

(1 point)
Responses

1:16, 3:18
1:16, 3:18

5:10, 20:40
5:10, 20:40

9:10, 45:40
9:10, 45:40

1:8, 2:18

Answer 1

A proportion means the two ratios are equal. Check by simplifying or cross-multiplying.

1) 1:16 vs 3:18 → 1/16 ≠ 3/18 (3/18 = 1/6)
2) 5:10 vs 20:40 → 5/10 = 1/2 and 20/40 = 1/2, or cross-multiply: 5·40 = 200 and 10·20 = 200 ✓
3) 9:10 vs 45:40 → 9/10 ≠ 45/40 (45/40 = 9/8)
4) 1:8 vs 2:18 → 1/8 ≠ 2/18 (2/18 = 1/9)

Therefore the pair that forms a proportion is: 5:10 and 20:40.