Let x be the elevation in thousands of feet for an archaeological site in southwestern U.S. Let y be the percentage of unidentified artifacts at a given elevation. Suppose that the following data were obtained for a collection of archaeological sites in New Mexico.

x = 5.25, 5.5, 5.75, 6.25, 6.5

y = 12, 38, 38, 42, 59

Find the equation of the least squares line