Consider the following table.
x 1 3 5 7 9
y 9 7 7 3 2
(a) find the equation of the least-squares line for the data.

y = -0.9x+10.1

Step-by-step explanation:

The equation of the line is:

You have been asked to stimate m and b. To do so, first find the product between each pair of x and y and the value of x squared:

Then calculate the total sum of all columns:

m can be calculated following the next equation:

where n is the number of (x, y) couples (5 in our case).

Replacing the values calculated previously:

For b:

In the figure attached you can see the points given and the stimated line.