A pharmaceutical manufacturer wants to determine the concentration of a key component of cough medicine that may be used without the drug causing adverse side effects. As part of the analysis, a random sample of 45 patients is administered doses of varying concentration, and the severity of side effects is measured. The results include x = 88.9, y = 165.3, SSx = 2133.9, SSxy = 4502.53, SSy = 12,500. Find the least squares estimates of the regression parameters. Assume x to be the independent variable and y to be the dependent variable. What does the parameters signify?