6.5B 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 unknown variable.

Front

If 13 out of 20 homes have a personal computer, how do you find the expected number of homes with a computer on a street with 60 homes?

Back

Set up the proportion: 13/20 = x/60, then cross-multiply and solve for x.

Front

What is the formula for finding the unit rate?

Back

The unit rate is found by dividing the quantity by the number of units, e.g., jumps per minute.

Front

If Jack jumps 40 times in 4 minutes, how many times does he jump in 1 minute?

Back

Jack jumps 10 times in 1 minute (40 jumps ÷ 4 minutes = 10 jumps/minute).

Front

Ingrid types 3 pages in the same time Tanya types 4.5 pages. How do you find how many pages Tanya types when Ingrid types 11 pages?

Back

Set up the proportion: 3/4.5 = 11/x, then cross-multiply and solve for x.

Front

What is the relationship between ratios and proportions?

Back

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

Front

How can you express a proportion as a fraction?

Back

A proportion can be expressed as a fraction by writing it in the form a/b = c/d.

Front

What does it mean if two ratios are equivalent?

Back

If two ratios are equivalent, it means they represent the same relationship between quantities.

Front

How do you find the missing value in a proportion?

Back

You can find the missing value by cross-multiplying and then dividing.