(3,2), (4,3), (5,2). 

Method of Least Squares: The straight line

y = a + bx

should be fitted through the given points (x₁,y₁), ..., (xₙ,yₙ) so that the sum of the squares of the distances of those points from the straight line is minimum, where the distance is measured in the vertical direction (the y-direction).