Categories
1. What is Linear Regression ?

How to Find a Linear Regression Equation: Steps

Step 1: Make a chart of your data, filling in the columns in the same way as you would fill in the chart if you were finding the Pearson’s Correlation Coefficient.

SUBJECTAGE XGLUCOSE LEVEL YXYX2Y2
14399425718499801
2216513654414225
3257919756256241
44275315017645625
55787495932497569
65981477934816561
Σ247486204851140940022

From the above table, Σx = 247, Σy = 486, Σxy = 20485, Σx2 = 11409, Σy2 = 40022. n is the sample size (6, in our case).

Step 2: Use the following equations to find a and b.

a = 65.1416
b = .385225

Find a:

  • ((486 × 11,409) – ((247 × 20,485)) / 6 (11,409) – 2472)
  • 484979 / 7445
  • =65.14

Find b:

  • (6(20,485) – (247 × 486)) / (6 (11409) – 2472)
  • (122,910 – 120,042) / 68,454 – 2472
  • 2,868 / 7,445
  • .385225

Step 3: Insert the values into the equation.
y’ = a + bx
y’ = 65.14 + .385225x

That’s how to find a linear regression equation by hand!

Leave a Reply

Your email address will not be published. Required fields are marked *