Finding Slope and Y Intercept from Graphs and Tables

How do you calculate the slope or rate of change for a graphed line?

• Pick two pretty points; make a right triangle; calculate run over rise

• Pick two pretty points; make a right triangle; calculate rise over run

• Make a right triangle and use a² + b² = c²

• Look to see where the line crosses the y-axis

What is the y-intercept? Choose ALL answers that apply.

• The rise over the run

• Where the line crosses the y-axis

• The rate of change

• The beginning value, when x = 0

What is the slope of the graphed line?

• ¼

• -¼

• 4

• -4

What is the y-intercept for the graphed line?

• 0

• -1.25

• -5

• There is no y-intercept

How do you find the rate of change or slope when you are given a table?

• Find out the y-value when the x-value is 0

• Add all the numbers up and divide by the number of numbers

If you are given a table, and the table shows you the x-value of 0, how do you find the y-intercept from the table?

• If you know the x-value is 0, then the y-intercept is the y-value that goes with the x-value of 0.

• There is no way to find a y-intercept from a table

• The y-intercept is the all the y-values averaged together

• The y-intercept is the difference between the largest y-value and the smallest y-value

If you are given a table and it DOES NOT show you the x-value of 0, how do you find the y-intercept from the table?

• The y-intercept is always 0
  

• There is no way to find a y-intercept from a table

• First, find the slope of the line using the slope formula, then using the formula y=mx+b, substitute in the slope for m, an ordered pair from the table for x and y, and solve for b.
  

• The y-intercept is all the y-values averaged together
  

A supermarket advertises a new product by offering samples to customers. The table shows the number of samples distributed each hour. At what rate does the supermarket distribute samples?

• 36 samples per hour

• 28 samples per hour

• 38 samples per hour

• 26 samples per hour

Look at the graph. Which best describes the slope of the line in the graph?

• Increasing 3 miles per minute

• Decreasing 2 miles per minute
  

Look at the graph. Which best represents the y-intercept of the line shown in the graph?

• After 0 minutes, 0 miles have been traveled