The personnel department of a certain industrial firm used 12 subjects in a study to determine the relationship between job performance rating (y) and scores of four tests. The data are as follows:...

The personnel department of a certain industrial firm used 12 subjects in a study to determine the relationship between job performance rating (y) and scores of four tests. The data are as follows:
Estimate the regression coefficients in the model y = b o + b1x1 + b2x2 + b3x3 +b4x4.