Proportionality (Topic 2) - Study Guide

Front

What is proportionality?

Back

Proportionality is a relationship between two quantities where their ratio remains constant. If one quantity increases, the other increases at a consistent rate.

Front

Define direct proportion.

Back

Direct proportion occurs when two quantities increase or decrease together, maintaining a constant ratio. For example, if you double one quantity, the other also doubles.

Front

What is the formula for finding a proportional relationship?

Back

The formula is \( y = kx \), where \( k \) is the constant of proportionality.

Front

If 4 miles corresponds to 2 hours, how many miles correspond to 1 hour?

Back

2 miles.

Front

What does it mean if two quantities are inversely proportional?

Back

If two quantities are inversely proportional, as one quantity increases, the other decreases, such that their product remains constant.

Front

Example of inverse proportion: If 5 workers can complete a task in 10 hours, how long will it take 10 workers?

Back

5 hours.

Front

What is a constant of proportionality?

Back

The constant of proportionality is the constant \( k \) in the equation \( y = kx \), representing the ratio of the two quantities.

Front

How do you determine if two ratios are proportional?

Back

Two ratios \( \frac{a}{b} \) and \( \frac{c}{d} \) are proportional if \( ad = bc \).

Front

What is a unit rate?

Back

A unit rate is a comparison of two different quantities when they are combined together, expressed as a quantity of one. For example, 60 miles per hour.

Front

If a recipe requires 4 cups of flour for 2 cakes, how much flour is needed for 5 cakes?

Back

10 cups of flour.