1, a, b, c and d are all non-zero. If A: B = C: D, then d: c = b: a .................................................... (y).

2. If ab+5 = 12, A and B are inversely proportional. (Y)

3, x–y = 0, and both x and y are not zero, then x and y are not proportional. (Y)

4, the distance is certain, and the diameter of the wheel is directly proportional to the number of revolutions. (N)

5. The actual distance is certain, and the distance on the map is proportional to the scale. (Y)

6. If the interest rate of a five-year time deposit is fixed, the principal of the five-year time deposit is directly proportional to the interest. …………( Y)

7. On the same map, the longer the distance between A and B, the longer their actual distance. ................. (noun)

8. It is known that the ratio of the minuend to the difference is 5: 3, the minuend is 100, and the minuend is 160. ………………………………(N)