Equations for Proportional Relationships

Front

What is a proportional relationship?

Back

A proportional relationship is a relationship between two quantities where the ratio of one quantity to the other quantity is constant.

Front

What is the constant of proportionality?

Back

The constant of proportionality is the constant value (k) that relates two proportional quantities, often represented in the equation y = kx.

Front

If y = 6x, what is the constant of proportionality?

Back

The constant of proportionality is 6.

Front

How do you find the constant of proportionality from a table of values?

Back

Divide the value of y by the value of x for any pair of corresponding values; if the ratio is constant, that value is the constant of proportionality.

Front

What equation represents the proportional relationship of earning $30 for every 5 hours babysitting?

Back

y = 6x, where y is the total earnings and x is the number of hours.

Front

If 624 calories are in 3 servings, how many calories are in one serving?

Back

208 calories per serving.

Front

What is the formula to find the constant of proportionality?

Back

k = y/x, where k is the constant of proportionality, y is the output, and x is the input.

Front

In the equation y = ½x, what is the constant of proportionality?

Back

1/2.

Front

If a car travels at a constant speed of 45 mph, what is the constant of proportionality in terms of distance and time?

Back

The constant of proportionality is 45, meaning for every hour, the car travels 45 miles.

Front

What does it mean if a relationship is not proportional?

Back

If a relationship is not proportional, the ratio of y to x is not constant; it varies with different values.