Constant Proportionality from Tables
Constant of Proportionality - Equations
Constant of Proportionality and Equations
Using k to solve problems
100

Drew paints portraits.  Find the constant of proportionality if it is a proportional relationship (with correct units!)

Number of portraits               Time (in hours)

           1                                          5

           2                                          10

           3                                          15

           4                                          20


What is 5 portraits per hour?

100

James sends 45 emails in 15 minutes. How many emails did he send per minute?

He sent 3 emails per minute.

This means the constant of proportionality is 3.

100
Find the constant of proportionality: y = 7x

What is 7?

100

The table shows the distance covered by a train over time.  How far would the train go in 24 hours?

Distance (km)      50          60          70           80

Time (in hours)     10          12         14           16

What is 120 miles?

200

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


Cups Sold               3         5        7         9

Earnings ($)           12        20      28       36


What is y = 4x?

200

Liana earned $640 in a 40 hour work week. What is Liana's hourly rate of pay?

Liana earns $16 per hour. 

This means the constant of proportionality is 16.

200

Find the constant of proportionality: y = (2/3)x

What is 2/3?

200

Andrea rents a bike for a day.  The rental charges are determined by the equation: R = $0.50d, where R is rental charges and d is number of days.  Find the cost of a 7 day bike rental.

What is $3.50?

300

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

What is not proportional?

300

A helicopter propeller spins 2500 revolutions in 4 minutes. What is the constant of proportionality for revolutions per minute.

k = 626.25

300

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

Daisy made envelopes from paper.  Figure out the incorrect information and replace it with the correct value.

Number of envelopes          1         2          3         4

Number of sheets               2         4          6         12


What is (4,8)?

400

A ferry transports bikes to an island.  Write the equation


Number of bikes              10             12             14             16

Number of trips               5                6               7               8

What is y = 0.5x?

400

Is this a proportional relationship?

Time (h)      Quantity

   1                   4

   2                   8

   3                   14

No.

400

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

At a party, the number of cold drink bottles consumed can be determined by the equation B = 3G, where B is the number of bottles and G is the number of guests.  Find the number of guests if there are 51 bottles.

What is 17 guests?

500

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


Number of comics             2             4             6             8

Price (dollars)                   6            12            16           24


What is not proportional?

500

Is this a proportional relationship?

#of tickets       cost

  2                     3

  4                     6

  6                     9

Yes. The constant of proportionality is 1.5.

500

Is this a proportional relationship?

Time (h)     Quantity (barrels)

   1                   2.75

   2                   5.5

   3                   8.25

Yes, and the constant of proportionality is 2.75.

500

Find the amount of seed packets you need to have 1000 plants and there are 10 seeds in a pack.

What is 100 packets?