00:01
In this exercise, we are given the data set shown here, and we are also told that the estimated linear regression line is given by the equation shown at the top here.
00:13
For part a, we are asked to find the sum of squares due to error, the total sum of squares, and the sum of squares due to regression.
00:24
Now, the sse is given by this formula.
00:39
Esst is given by this formula, and the ssr by this formula.
01:06
Now i'm going to solve these directly on the excel spreadsheet.
01:09
The first step would be to find the predicted values for y using our regression equation.
01:20
So the regression equation estimates y as 0 .2 plus 2 .6 times the x value.
01:33
So we can do this for each x value and we get the estimated y values.
01:41
It's called that y hat.
01:47
Now for the squared errors, let's first find, for the sum of squared errors, let's first find the squared errors.
02:02
So for each data pair, it's the y value, yi, subtracting the predicted value, and then squared.
02:26
And then we do this for each data pair.
02:30
And then we want to find the sum of them.
02:41
And now for the sst, we can first find the squared deviations.
02:55
This is by, well let's first find the average y value...