Answer:

Where:
With these we can find the sums:
And the slope would be:
Nowe we can find the means for x and y like this:
And we can find the intercept using this:
So the line would be given by:
And for this case the value of the slope m = 6.9096 means that for every increase of 1 unit in the number of years we have an increase of approximately 6.9096 in the grades of the test.
Step-by-step explanation:
Data given:
x: 3, 4, 4, 5, 3, 6, 2, 7, 3
y: 61, 68, 75, 82, 73, 90, 58, 93, 72

Where:
With these we can find the sums:
And the slope would be:
Nowe we can find the means for x and y like this:
And we can find the intercept using this:
So the line would be given by:
And for this case the value of the slope m = 6.9096 means that for every increase of 1 unit in the number of years we have an increase of approximately 6.9096 in the grades of the test.