Writing and Solving Proportions

Front

What is a proportion?

Back

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

Front

How do you solve a proportion?

Back

To solve a proportion, cross-multiply the terms and then solve for the variable.

Front

If 12 ounces of shampoo lasts 16 weeks, how long will 18 ounces last?

Back

24 weeks.

Front

What is the formula to find the expected number of items based on a proportion?

Back

Expected number = (part/whole) * total.

Front

If 13 out of 20 homes have a computer, how many homes in a neighborhood of 60 would have a computer?

Back

39 homes.

Front

What does it mean to cross-multiply in a proportion?

Back

Cross-multiplying means multiplying the numerator of one ratio by the denominator of the other ratio.

Front

Solve for x: 5/10 = x/20

Back

x = 10.

Front

If Nathan packs 39 boxes in 3 hours, how many boxes can he pack in 8 hours?

Back

104 boxes.

Front

What is the relationship between ratios and proportions?

Back

Ratios are comparisons of two quantities, while proportions show that two ratios are equal.

Front

Solve for x: 3x = 78

Back

x = 26.