In a simple linear regression model, you have the following data points for the independent variable (X) and dependent variable (Y):
X: [2, 4, 6, 8, 10]
Y: [5, 7, 8, 12, 15]
What is the slope (a) of the regression line in this model?
To find the slope (a) in a simple linear regression model, you can use the following formula:
a = [n(ΣXY) – (ΣX)(ΣY)] / [n(ΣX^2) – (ΣX)^2]
Where:
- n is the number of data points.
- ΣXY is the sum of the product of X and Y.
- ΣX is the sum of X values.
- ΣY is the sum of Y values.
- ΣX^2 is the sum of the squares of X values.
Given the data: X: [2, 4, 6, 8, 10] Y: [5, 7, 8, 12, 15]
First, calculate the necessary sums:
- n = 5
- ΣX = 2 + 4 + 6 + 8 + 10 = 30
- ΣY = 5 + 7 + 8 + 12 + 15 = 47
- ΣXY = (25) + (47) + (68) + (812) + (10*15) = 10 + 28 + 48 + 96 + 150 = 332
- ΣX^2 = (2^2) + (4^2) + (6^2) + (8^2) + (10^2) = 4 + 16 + 36 + 64 + 100 = 220
Now, plug these values into the formula to calculate the slope (a):
a = [5(332) – (30)(47)] / [5(220) – (30)^2] a = [1660 – 1410] / [1100 – 900] a = 250 / 200 a = 1.25
To find the slope (a) in a simple linear regression model, you can use the following formula:
a = [n(ΣXY) – (ΣX)(ΣY)] / [n(ΣX^2) – (ΣX)^2]
Where:
- n is the number of data points.
- ΣXY is the sum of the product of X and Y.
- ΣX is the sum of X values.
- ΣY is the sum of Y values.
- ΣX^2 is the sum of the squares of X values.
Given the data: X: [2, 4, 6, 8, 10] Y: [5, 7, 8, 12, 15]
First, calculate the necessary sums:
- n = 5
- ΣX = 2 + 4 + 6 + 8 + 10 = 30
- ΣY = 5 + 7 + 8 + 12 + 15 = 47
- ΣXY = (25) + (47) + (68) + (812) + (10*15) = 10 + 28 + 48 + 96 + 150 = 332
- ΣX^2 = (2^2) + (4^2) + (6^2) + (8^2) + (10^2) = 4 + 16 + 36 + 64 + 100 = 220
Now, plug these values into the formula to calculate the slope (a):
a = [5(332) – (30)(47)] / [5(220) – (30)^2] a = [1660 – 1410] / [1100 – 900] a = 250 / 200 a = 1.25