Slope & Y-Intercept In Context

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.

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.

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 [850 + 250 deposit] Image from http://pixabay.com/en/computer-hardware-keyboard-modern-156513/

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

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)

Wheelchair Access Ramp y = -1/12x 4 = -1/12x -48 = x The ramp will need to be 48 feet long. Image from http://wheelchairassistance.com/wheelchair-ramp/trifold-wheelchair-ramps.php