Constant Proportionality

Constant Proportionality (k)

The constant multiple in y = kx

Where k is the constant multiple. 

To find k you can use-
 $k\ =\ \frac{y}{x}$ 

How to spot k CONSTANT PROPORTIONALITY

• Unit Rate (each, every, per, a)

• Examples: 55 miles per hour, $4.25 per pound, 0.1 kilometer per minute

• A constant rate - $30 for 5 hours, $32 every 4 months

How to FIND k (constant proportionality)

• If given a UNIT RATE (55 miles per hour) K equals the number you are multiplying by. k = 55
  

• y = 55x

Multiple Choice

k represents

• the constant of proportionality

• the king

• ketchup

• a strikeout

Multiple Choice

Which equation matches the constant of proportionality?

• x = y

• y = x

• y = kx

• l x w

Multiple Choice

Identify the constant of proportionality.

• k = 2x

• k = 2

• k = 4

• none (not proportional)

Multiple Choice

The constant of proportionality in the equation y = ½x is _______. 

• x
• y
• 1/2
• 2

Multiple Choice

The constant of proportionality can be found by finding the ______ ______.

• unit rate

• ratio rate

• proportion answer

• rational number

How to FIND k (constant proportionality)

• If given a constant rate ($30 for 5 hours) use  $k=\frac{y}{x}\ \rightarrow\ k\ =\ \frac{30}{5}\rightarrow\ k\ =6$ 

• y = 6x, Olivia is paid $6 per hour for babysitting. The equation will find how much she will be paid for x amount of hours

How to FIND k (constant of proportionality)

• From a TABLE use  $k\ =\ \frac{y}{x}$  

• From a GRAPH use  $k\ =\ \frac{y}{x}$  

Multiple Choice

Which equation helps you solve for k?

• $k\ =\ \frac{x}{y}$

• $k\ =\ \frac{y}{x}$

• k = y + x

• k = 2x

Multiple Choice

What is the constant of proportionality for this table?

• $1/9 per hour

• $9 per hour

• $8 per hour

Multiple Choice

Write the equation for the table given.

• y = 16x

• y=8x

• y=12x

Multiple Choice

Determine the missing value in the table.

• 15

• 3

• 1/3

• 9

Multiple Choice

What is the constant of proportionality?

• 15

• 3

• 1/3

• 9

Multiple Choice

What is k in this proportional relationship?

• 60

• 120

• 1

• 180

Multiple Choice

What is the constant of proportionality for the following graph?

• 80

• 20

• 40

• 160

Multiple Choice

Which statement matches the graph?

• Taylor can write 6 words per minute

• Taylor can write 25 words per minute

• Taylor can write 50 words per minute

• Taylor can write 150 words per minute