7.4A 7.4D rates/ proportions

Front

What is a rate?

Back

A rate is a ratio that compares two different quantities, often expressed as a fraction. For example, speed is a rate that compares distance to time.

Front

What is a proportion?

Back

A proportion is an equation that states that two ratios are equal. For example, if a/b = c/d, then a, b, c, and d are in proportion.

Front

How do you find a percentage of a number?

Back

To find a percentage of a number, convert the percentage to a decimal and multiply it by the number. For example, 20% of 60 is 0.20 * 60 = 12.

Front

If 3 photos take up 24 MB, how much space does 1 photo take up?

Back

1 photo takes up 8 MB (24 MB ÷ 3 photos = 8 MB per photo).

Front

If 1 km = 0.621371 miles, how many miles are in 40 km?

Back

40 km is approximately 24.85 miles (40 km * 0.621371 miles/km).

Front

What is the formula for calculating total cost based on unit price?

Back

Total cost (y) = Unit price (x) * Quantity (number of units).

Front

How do you set up a proportion to solve for an unknown?

Back

To set up a proportion, write two ratios equal to each other and cross-multiply to solve for the unknown. For example, if a/b = c/x, then a*x = b*c.

Front

What is the relationship between rates and unit rates?

Back

A unit rate is a rate in which the second quantity is 1. For example, if a car travels 300 miles in 5 hours, the unit rate is 60 miles per hour.

Front

How do you convert a fraction to a percentage?

Back

To convert a fraction to a percentage, divide the numerator by the denominator and multiply by 100. For example, 1/4 = 0.25 * 100 = 25%.

Front

What is the significance of equivalent ratios?

Back

Equivalent ratios are ratios that express the same relationship between quantities. They are important for solving proportions and understanding rates.