Constant of Proportionality Concepts

Directly proportional: when quantities increase and decrease at the ____ ____.

constant of proportionality: the ratio between two ________ ____________ quantities.

Equation for CoP: ____

k=________

k=___

When finding the CoP in table, ONLY use the first row and do...

• y - x

• y/x

• y + x

• y times x

When finding CoP in a graph, find a nice point (where line goes through a corner), draw left to get y, draw down to get x and then do...

• y/x

• y times x

• y + x

• y - x

When finding CoP in an equation, solve for y if the equation is not already in the form y=kx. The Cop is then simply _?

• CoP

• x

• y

• k

The CoP is used to _______ items/situations that are originally not comparible because they are in simple ratios, not per 1.

When interpretting, the CoP means how many y's per 1 x. So, if you have c=10s where c = cost and s = # of shirts, what does 10 mean?

• 10 shirts total

• $10 total

• 10 shirts per 1 dollar

• $10 per shirt