Proportions and Rates Review

Front

What is a proportion?

Back

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

Front

What is a rate?

Back

A rate is a ratio that compares two quantities with different units.

Front

How do you calculate percent change?

Back

Percent change is calculated by taking the difference between the new value and the old value, dividing by the old value, and then multiplying by 100.

Front

What is the formula for finding the total amount paid with interest?

Back

Total Amount = Principal + (Principal x Rate x Time) where Rate is in decimal form.

Front

What does constant of proportionality mean?

Back

The constant of proportionality is the constant value (k) that relates two proportional quantities.

Front

If a computer costs $800 and has a 15% interest rate, how much interest will be paid after 5 years?

Back

Interest = Principal x Rate x Time = $800 x 0.15 x 5 = $600.

Front

What is the formula to find the constant of proportionality from a table of values?

Back

k = y/x, where y is the dependent variable and x is the independent variable.

Front

How do you express a ratio?

Back

A ratio can be expressed as a fraction, with a colon, or with the word 'to' (e.g., 3:4, 3/4, or 3 to 4).

Front

What is the relationship between ratios and proportions?

Back

Ratios are comparisons of two quantities, while proportions state that two ratios are equal.

Front

How do you find the percent of a number?

Back

To find the percent of a number, multiply the number by the percent (in decimal form).