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### Course: Operations and Algebraic Thinking 222-226>Unit 1

Lesson 5: Graphs of proportional relationships

# Interpreting graphs of proportional relationships

Worked example interpreting graphs of proportional relationships.

## Want to join the conversation?

• whats the diffrence between linear and porportional
• linear means it is a line proportional means it is a line that goes to (0,0)
• whats the difference between linear and porportional
• Linear lines are straight lines on a graph

proportional lines are straight lines on a graph that start at the origin

also linear lines are defined by the equation y = mx + b

proportional lines are defined by the equation y = kx

hope this helped
• and when do we use this in life?
• Honestly? Almost never. But if you want a well-paying job later in life, that'll most likely require college experience. And to get into college you'll need to take tests. And these tests will be about subjects like this. So really what you are learning now in school and on Khan will be impacting you on unimaginable scales later in life.
• Hello? Anybody here? All these comments are really old.
• If you hit the sort by button above the comments you will see comments from a little more recently.
• how would i do this on a bigger graph in the thousands
• There are two ways to scale a graph, instead of going by 0, 1, 2, 3 (and negatives to the left or down), the scale can be changed to 0, 1000, 2000, 3000, etc, including negatives without even having to change the size of the graph. The other option is to define each of the x and y axis in terms of larger numbers such as x represents dollars (in thousands).
• What does the K mean in this Question?
• This is algebra. K is an algebraic term.
• The second one is tricky
• why is the constant always k?
(1 vote)
• From what I Googled, and other comments I've seen in the past, we don't know fully. You could use any other symbol to represent the constant of proportionality. But it could be in reference to the German word `Konstante`, which means-you guessed it! Constant. And since, from what I gather, Germans Mathmaticians made major contributions to the math world, it could be a little tribute to them.

Whatever the true reason is, I hope this helped, have a lovely day. 😊