There are a variety of situations in which sats of (x y) data obey linear relationship with a common intercept. Such data could be analyzed in an obvious simplistic way carrying out an ordinary least-squares fit for each set and avearging a posteirori the values of the intercept. However the values of the slopes would be influenced by the fact that the intercepts in each fit are not identical. The problem of multiple linear least-squares fits with a common intercept ha a mathematically rigorous yet simple solution that has padogogical value of illustrating the basic principle of least-squares fitting.