Constant Proportionality from Tables
Constant of Proportionality from Graphs
Constant of Proportionality from Words
Constant of Proportionality and Equations
100

The table shows the amount earned by Harry for selling ice cream.  Find k.


Cups Sold = x              3         5        7         9

Earnings ($)  = y         12        20      28       36


k = 4

100

What is K?

k = 1.2

100

To help the environment and make some extra money, Julie takes her empty cans to the Cash Not Trash recycling shop. The shop pays cash based on the total weight of the cans Julie brings in for recycling. There is a proportional relationship between the weight (in pounds) of the cans Julie brings into the shop, x, and the amount (in dollars) the shop pays Julie, y.

Last month, Julie brought 5 pounds of cans into the shop and was paid $2. Find the constant of proportionality with correct units.

$0.40/pound

100

Find the constant of proportionality: C = (2/3)m

What is 2/3?

200

Fred wrote notes during an exam.  Find k (with correct units) if it is a proportional relationship.


Notes (pages)          8             9               10            11

Time (in hours)        16           18              20            23

It is not proportional, there is no k. 

200

Find the constant of proportionality with correct units

5 gallons per min

200

Michael's class is having a holiday party, and he is in charge of bringing juice. He decides to bring powdered juice mix and add water to it at school. There is a proportional relationship between the volume of water Michael uses to make the juice (in liters), x, and the number of scoops of juice mix he uses, y.

To make the juice, Michael combines 4 liters of water and 12 scoops of juice mix. What is k?

k = 3

200

Daisy made bread.  The equation B = 4f shows the number of breads basked based on the amount of flour used.  Where B is the number of bread loaves made and f is the cups of flour used.  Find the constant of proportionality.

What is 4 loaves/cup?

300

A ferry transports bikes to an island.  Write k. 


Number of bikes (x)              10             12             14            

Number of trips (y)              5                6               7              

k = 0.5

300

Find k.

k = 3

300

In a flash of sheer brilliance, Zachary invents a time machine! The machine uses a small nuclear reactor to generate the electricity it needs to travel back in time. There is a proportional relationship between how many years Zachary wants to travel back in time, x, and how much electricity (in megawatts) his time machine needs, y.

Zachary's time machine needs 14 megawatts of electricity to travel back 7 years.  Write the k for this problem. 

k = 2

300

The number of milk bottles sold can be determined by the equation P = 0.35n, where P is the number of bottles of milk and n is the number of boxes opened.  Find the constant of proportionality with correct units.

What is 0.35 bottles per box?

400

Alice bought comics.  Find the k (with correct units) if the table shows a proportional relationship.


Number of comics             2             4             6            

Price (dollars)                   6            12            16           


It is not proportional, there is no k. 

400

Find the constant of proportionality with correct units

60 miles per hour

400

Susan measures the length of some items in feet but needs to convert them all to inches. She looks up each measurement in feet online to find the correct number of inches. There is a proportional relationship between the number of feet, x, and the number of inches, y.

An item that is 4 feet long is 48 inches long.   Write the k with correct units.

 12in per foot

400

In a laboratory, scientists performed chemical reactions.  The amount of product formed by a reaction can be determined by P = 0.25r, where P is the product and r is the amount of reactants used.  Find k with correct units.

What is 0.25 product per reactant?