Unit 5 Flashcard #2 Practice (Proportions)

Front

What is a proportion?

Back

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

Front

How do you find a percentage of a number?

Back

To find a percentage of a number, multiply the number by the percentage (in decimal form). For example, to find 20% of 45, calculate 45 * 0.20 = 9.

Front

What is the formula to convert seconds to minutes?

Back

To convert seconds to minutes, divide the number of seconds by 60.

Front

If 8 is what percent of 20, how do you calculate it?

Back

To find what percent 8 is of 20, use the formula: (part/whole) * 100. So, (8/20) * 100 = 40%.

Front

What does it mean if two ratios are equivalent?

Back

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

Front

How can you express a ratio as a fraction?

Back

A ratio can be expressed as a fraction by placing the first quantity over the second quantity. For example, the ratio 3:4 can be expressed as 3/4.

Front

What is the relationship between fractions and proportions?

Back

Fractions can be used to express proportions, as a proportion is essentially an equation that equates two fractions.

Front

How do you solve for an unknown in a proportion?

Back

To solve for an unknown in a proportion, cross-multiply and then divide. For example, in the proportion a/b = c/d, you can find a by calculating a = (b * c) / d.

Front

What is the percent increase formula?

Back

The percent increase formula is: ((new value - old value) / old value) * 100.

Front

What is the percent decrease formula?

Back

The percent decrease formula is: ((old value - new value) / old value) * 100.