equation of LOBF

avatar
Created by
Denuka Mahenthiran

Cards (7)

  • LOBF is also known as regression line
  • 𝑬𝒒𝒏 𝒐𝒇 ��𝑢����: οΏ½οΏ½ = 𝒂𝒙 + b
  • where a is the gradient and b is the y-intercept
  • gradient, a – the rate of increase of the response variable in relation to explanatory variable
  • y-intercept, b – the value of the response variable when explanatory variable is 0
  • Drawing Regression Line:
    1. Use equation of LOBF to calculate coordinates of two points.
    2. Plot these points on the scatter graph.
    3. Join them up with a straight line (extend you line a little if you need to)
  • Finding Equation of LOBF/Regression Line:
    1. Select 2 points on the graph – pick 2 points on the corners of the square for more accurate readings. Call these 2 points (π‘₯1, 𝑦1 ) and(π‘₯2, 𝑦2 )
    2. Calculate the gradient, a. --> 𝒂 = π’šπŸ βˆ’ π’šπŸ π’™πŸ βˆ’ π’™πŸ
    3. . Find the y-intercept, b. You could do this by:
    4. a.Read the point of the graph by extending the LOBF.
    5. b. Use the formula 𝑏 = 𝑦1 βˆ’ π‘Žπ‘₯1 using one of the 2 points you used for the gradient
    6. Write the equation in the form π’š = 𝒂𝒙 + 𝒃 with the correct values for a and b