Students should understand that graphing a proportional relationship will always have a y-intercept through the origin (0, 0). Students should determine the slope from a proportional graph by finding the value of the y-coordinate when the x-coordinate is 1 and from a proportional table by finding the value of the output when the input is 1. Students should use either a table or graph to determine the slope of a line and the y-intercept of the line.

 

 

8.4 Proportionality. The student applies mathematical process standards to explain proportional and non-proportional relationships involving slope. The student is expected to:

(C) use data from a table or graph to determine the rate of change or slope and y-intercept in mathematical and real-world problems