Proportional Relationship Basics
What is a proportional relationship?
A relationship between two quantities where the ratio is constant.
What is constant of proportionality?
It is the ratio of the amounts y and x
What does the graph of a proportional relationship look like?
A straight line that passes through the orgin (0,0).
What do you notice about the ratios of y to x in a table of proportional relationships?
The ratios is always the same or constant.
If 3 apples cost $6, how much would 1 apple cost?
$2 per apple
How can you tell if two quantites in a table are proportional?
If the ratio between corresponding values is constant.
How many miles can he drive per hour?: 180 miles in 3 hours.
60 miles per hour
If the graph of a proportional relationship passes through the point (4, 12), what is the constant of proprtionality?
3
If a table shows x = 2, y = 6, x = 4, y = 12, what is the constant of proportionality?
3
A car travels 300 miles using 10 gallons of gas. How many miles can the car travel per gallon?
30 miles per gallon.
if y = 4x, what is the constatnt of proportionality?
4
If 5 apples cost $10, what is the cost per apple
$2 per apple
A graph shows that for every 2 units of x, y increases by 5. What is the equation of the proportional relationship?
y = 2.5x
In a table, if x = 1, y = 5, x = 2, y = 1-, write the equation of the proportional relationship.
y = 5x
If it takes 4 hours to make a batch of cookies, how many batches can you make in 7 hours?
14 batches
True or False: In a proportional relationship, the graph is a straight line that does not pass through the orgin.
False, it passes through the orgin.
You can buy 12 pencils for $3. What is the cost per pencil?
$0.25 per pencil
If a table showed:
x: 2, 4, 6
y: 8, 16, 24
What would the ordered pairs be?
(2, 8), (4, 16), (6, 24)
If the table shows x = 3, y = 9, x = 6, y = 18, x = 9, y = 27, write the equation of the proportional relationship.
y = 3x
At the store, 5 pounds of banans cost $4.50. How much do 3 pounds cost?
$2.70
What is the equation form of a proprtional relationship?
y = kx
A car travels 150 miles on 5 gallons of gas. What is the rate in miles per gallon.
30 miles per gallon.
If the ratio follows the orgin what would the ratio be and how would you write it?
Ratio: 0
0:0, 0/0, or 0 to 0
If a table shows x = 5, y = 10, x = 10, y = 20, x = 20, y = 40, write the equation of the proportional relationship.
y = 2x
A machiene fills 250 bottles of water in 10 minutes. How many bottles can it fill in 35 minutes?
875 bottles