In an area of russia records were kept on the relationship between the rainfall (in inches) and the yield of wheat (bushels per acre). the data for a 9 year period is as follows:

rain fall, x 13.1 11.4 16.0 15.1 21.4 12.9 9.6 18.2 18.6
yield, y 48.5 44.2 56.8 80.4 47.2 29.9 74.0 74.0 76.8
the equation of the line of least squares is given as ŷ = -9.12+ 4.38x. what would be the expected number of inches of rain if the yield is 60 bushels of wheat per acre?
(a) 11.62 (b) 64.74 c) 253.68 (d) 15.78 ans: c plug y= 60 and solve for x.