In a proportion, the first and the fourth terms are called means and the second and the third terms are called extremes.

To determine a ratio, the two quantities should be of the same kind but can have different units.

In inverse proportion, an increase in the first quantity causes a decrease in the second quantity.

In a proportion, if the fourth term is greater than the third term, then the second term may not be greater than the first term.

In a proportion, the product of extremes may or may not be equal to the product of means.

17 : 50 < 2 : 3

2.63 : 5.78 > 7 : 12

$$2\frac{3}{4} : 1\frac{2}{5} > 2\frac{1}{3} : 1\frac{4}{5}$$

$$3\frac{2}{5} : 2\frac{3}{4} < 17.2 : 12.5$$

What is the fourth proportional to 7, 14 and 16?

What is the value of x, if 4 : 12 :: 18 : x?

What is the mean proportional between 7 and 343?

If 4 kg apples cost ₹ 235, what is the cost of 7 kg apples?

What is the value of x, if 6.25 : x :: 5 : 4?

What is $$\frac{975}{655}$$reduced to its lowest terms?

If the cost of 15 notebooks is ₹ 240, what is the cost of 12 notebooks?

The quantity of rice sold by two shopkeepers is in the ratio 2 : 5. If the second shopkeeper sold 25 kg of rice, what quantity of rice did the first shopkeeper sell?