Proportional Relationships
What makes a Graph Proportional?
Straight Line
Starts at Origin
Sahil hit 37 out of 50 balls during batting practice. What percent of the balls did Sahil hit?
74%
$30 dinner; 8% tax
$32.40
$60 shoes; 15% discount
$51
$850, 6%, 3 years
$153
How do you find Constant?
y / x
At a movie theater, the ratio of comedy to action movies is 2 : 3. What percent of the movies are action movies, if the movie theater only shows comedy and action movies?
60%
$15 taxi ride; 10% tip
$16.50
$96 dress; 35% discount
$62.40
Megan opened a savings account with a
$500 deposit. The account pays 1.25% simple interest each year. If she neither adds nor withdraws money from the account, how much interest will she earn after
3 years?
$18.75
Find the Constant
x y
2 1
4 2
1/2 or 0.5
12.5 inches to 18.5 inches
(New - Old) / Old x 100
48% Increase
Carmen wants to subscribe to a streaming service that costs $42.99 per month. The sales-tax rate in her city is 5%. What is the total cost of the streaming service each month?
$45.14
A fabric store is having a sale. Fleece fabric has an original price of $18 per yard. It is on sale for 30% off the original price. Find the sale price of the fleece fabric.
$12.60
Charles deposited $350 into a savings account. The account pays 3% simple interest on an annual basis. If he does not add or withdraw money from the account, how much interest will he earn after 9 months? Round to the nearest cent.
$7.88
x 4
__ = __
3 6
2
Last year, a total of 450 people attended the fall concert. This year, 720 people attend the fall concert. What is the percent of increase in attendance?
(New - Old) / Old x 100
60% Increase
A dog groomer charges $39.50. The dog’s owner wants to give a 15% tip. What would be the total cost, including the tip? Round to the nearest cent.
$45.43
The original price of a fitness tracker is $85. It is on sale for 10% off. What is the sale price of the fitness tracker?
$76.50
Mrs. Cousins works in a pool store and earns a 9.5% commission on every swimming pool she sells. How much commission would she earn for selling a pool that costs $5,600?
$532
9 81
__ = __
t 36
4
Last year, a popular brand of running shoes cost $75.99 per pair. The new model of the same shoe costs $95.99 per pair. What is the percent of increase in price for the pair of running shoes? Round to the nearest tenth if necessary.
(New - Old) / Old x 100
26.3% Increase
The wholesale cost of a cat carrier is $22.50. The markup for the carrier is 33.3%. Find the selling price of the carrier. Round to the nearest cent.
$29.99
An appliance store is having a 35%-off sale. Angela wants to purchase a new freezer that has an original price of $675. What is the sale price of the freezer?
$438.75
Sandi’s commission rate is 5.6%. She received a commission of $2,412 on vacation packages she sold in November. What is the amount of money in vacation packages that Sandi sold? Round to the nearest dollar.
$43,071