Setting Up Proportions

Front

What is a proportion?

Back

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

Front

How do you set up a proportion?

Back

To set up a proportion, you can use the formula \( \frac{a}{b} = \frac{c}{d} \), where a and b are part of one ratio, and c and d are part of another.

Front

If 14 sticks of pepperoni make 28 pizzas, how do you find the number of sticks needed for 36 pizzas?

Back

Set up the proportion: \( \frac{14}{28} = \frac{x}{36} \) and solve for x.

Front

What is the cross-multiplication method in proportions?

Back

Cross-multiplication involves multiplying the numerator of one ratio by the denominator of the other ratio, and vice versa, to find the unknown.

Front

If 3 meals cost $27, how do you find the cost of 12 meals?

Back

Set up the proportion: \( \frac{3}{27} = \frac{12}{x} \) and solve for x.

Front

What is the unit rate?

Back

The unit rate is a comparison of two different quantities when they are combined together, expressed as a quantity per one unit.

Front

How do you find the unit rate from a proportion?

Back

To find the unit rate, divide the numerator by the denominator of the ratio.

Front

If a car travels 420 miles in 8 hours, how do you find the distance it will travel in 12 hours?

Back

Set up the proportion: \( \frac{420}{8} = \frac{x}{12} \) and solve for x.

Front

What is a direct variation?

Back

Direct variation is a relationship between two variables in which one variable is a constant multiple of the other.

Front

How can you use proportions to solve real-world problems?

Back

You can use proportions to compare ratios and find unknown values in situations like scaling recipes, calculating costs, or determining distances.