Graphing proportional relationships example  8th grade  Khan Academy  Summary and Q&A
TL;DR
Graph a line with a proportional relationship and unit rate of 0.4. Determine the equation of the line.
Questions & Answers
Q: How do you determine if a relationship is proportional?
A proportional relationship can be identified if the equation is in the form y = kx, where k represents the constant of proportionality.
Q: What does the point (0,0) signify on the graph?
The point (0,0) indicates that when there are zero xvalues, there will also be zero yvalues. It is a fundamental property of proportional relationships.
Q: How can you find the slope of the graph?
The slope is determined by calculating the change in y divided by the change in x. In this case, the slope is 2/5 or 0.4.
Q: Why is the equation of the line y = 0.4x?
The equation of a proportional relationship is y = kx, where k is the constant of proportionality. In this case, the slope of 0.4 represents the value of k.
Summary & Key Takeaways

To graph a proportional relationship, the point (0,0) should be on the line. As x increases by 1, y increases by 0.4.

The point (5,2) is on the graph, indicating a change in x of 5 corresponds to a change in y of 2.

The slope of the graph, representing the rate of change, is calculated to be 0.4. The equation of the line is y = 0.4x.