Finding a missing number in a proportion

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal.

Front

How do you find a missing term in a proportion?

Back

To find a missing term in a proportion, you can use cross-multiplication. If a/b = c/d, then a*d = b*c.

Front

What is cross-multiplication?

Back

Cross-multiplication is a method used to solve proportions by multiplying the numerator of one ratio by the denominator of the other ratio.

Front

If 4:x = 2:8, what is the value of x?

Back

x = 16, because 4*8 = 2*x leads to x = 16.

Front

What is the relationship between the means and extremes in a proportion?

Back

In a proportion a/b = c/d, a and d are the extremes, and b and c are the means. The product of the means equals the product of the extremes.

Front

How can you check if two ratios form a proportion?

Back

You can check if two ratios form a proportion by cross-multiplying and seeing if the products are equal.

Front

What is the formula for finding a missing term in a proportion?

Back

If a/b = c/x, then x = (b*c)/a.

Front

If 15:9 = 5:x, what is the value of x?

Back

x = 3, because 15*3 = 5*9.

Front

What is the significance of equivalent ratios?

Back

Equivalent ratios are ratios that express the same relationship between numbers, and they are fundamental in solving proportions.

Front

How do you simplify a ratio?

Back

To simplify a ratio, divide both terms by their greatest common divisor (GCD).