Constant Proportionality from Tables
Constant of Proportionality and Equations
100

Drew paints portraits.  Find the constant of proportionality if it is a proportional relationship 

Time (in hours) = x             Number of portraits = y

           1                                          5

           2                                          10

           3                                          15

           4                                          20


5 portraits per hour

100

Find the constant of proportionality: y = 7x

k = 7

200

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


CoP = 4

200

Find the constant of proportionality:

C = 2/3 m

k = 2/3

300

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


Notes (pages)        8             9               10            11

Time (in hours)      18           19              20            21

It is not proportional, there is no CoP. 

300

Lia earns $39 for 3 hours of babysitting. There is a proportional relationship between the number of hours lia babysits, x, and the total amount of money she earns, y. What is the proportional relationsip equation?


y=13x

400

A ferry transports bikes to an island.  Write k (which is the CoP). 


Number of bikes (x)              10             12             14            

Number of trips (y)              5                6               7              

k = 0.5

400

William has a farm of hens. The number of eggs laid by the hens can be determined by the equation E=3h, where E is the number of eggs and h is the number of hens. Use the equation to find how many eggs can 27 hens lay.  

81 EGGS

500

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


Number of comics             2             4             6            

Price (dollars)                   6            12            18           


k = 3 dollars per comic

500

In a pizza shop, the number of pizzas prepared can be determined by the equation P=0.30c. Where P is the number of pizzas and c is the number of cups of cheese used. Use the equation to find how many cups of cheese is used to make 39 pizzas.

130 cups of cheese