1. Slope & Y-Intercept In Context

2. Learning Goal #2 for Focus 4 (HS.S-ID.C.7, 8 & 9, HS.S-ID.B.6, HS.F-IF.B.6): The student will be able to interpret linear models. 4 3 2 1
In addition to level 3.0 and above and beyond what was taught in class,  the student may:
· Make connection with other concepts in math
· Make connection with other content areas.
The student will be able to interpret linear models.
- Interpret slope in context of data.
- Write the line-of-best-fit for a scatter plot.
- Distinguish between correlation and causation.
- Use technology to calculate correlation coefficient.
The student will be able to:
- Determine if a scatter plot has positive or negative correlation and if the correlation is weak or strong.
- Use the correlation coefficient to interpret the strength of a correlation.
With help from the
teacher, the student has
partial success interpreting linear models or scatter plots.
Even with help, the student has no success understanding the concept of a linear models.

3. Using Slope-Intercept Form
In a real-life context the y-intercept often represents an initial amount and the slope often represents a rate of change.
Knowing this structure can help you understand equations, write equations in slope-intercept form and understand graphs.

4. Buying A Computer -50 (0, 850) $1,100 [850 + 250 deposit]
You are buying a computer on layaway. You make a $250 deposit and then make weekly payments.
The equation A = 850 – 50T represents this situation.
What is the slope?
What does it mean in this situation?
What is the y-intercept?
What is the original amount of the computer?
-50
(0, 850)
$1,100 [ deposit]
Image from

5. Access Ramps
Wheelchair access ramps must be built according to very precise specifications so that the ramps are not too steep to maneuver a wheel chair.
If one is standing at the top of the ramp, y stands for the height above the ground and x stands for the horizontal distance from the top.
The equation for the ramp is y = -1/12 x

6. y = -1/12x
What is the meaning of the y-intercept in this particular situation?
Suppose you wish to build a wheelchair accessible ramp into a building, and the first floor is 4 feet above the ground. Determine the how far out horizontally from the building should the ramp begin?
(x, 4)
(0, 0)

7. Wheelchair Access Ramp
y = -1/12x
4 = -1/12x
-48 = x
The ramp will need to be 48 feet long.
Image from