5.3 Writing Proportions

Front

What is a proportion?

Back

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

Front

How do you write a proportion from a word problem?

Back

Identify the two ratios in the problem and set them equal to each other.

Front

If the ratio of cats to dogs is 3 to 5, how can you express this as a fraction?

Back

The ratio can be expressed as 3/5.

Front

In the problem, 'If there are 25 dogs, how many cats are there?' how do you set up the proportion?

Back

Set up the proportion as 3/5 = x/25, where x is the number of cats.

Front

What is the cross-multiplication method in solving proportions?

Back

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

Front

Solve the proportion 3/5 = x/25. What is x?

Back

x = 15.

Front

What is the relationship between distance, rate, and time?

Back

Distance = Rate × Time.

Front

If Joseph drives 125 miles in 2 hours, what is his rate?

Back

His rate is 125 miles / 2 hours = 62.5 miles per hour.

Front

How do you set up a proportion to find how far Joseph can travel in 6 hours?

Back

Set up the proportion as 125/2 = x/6.

Front

Solve the proportion 125/2 = x/6. What is x?

Back

x = 375 miles.