The personnel director for Electronics Associates developed the following estimated regression equation relating an employee's score on a job satisfaction test to his or her length of service and wage rate.
 = 14.4 - 8.69x1 + 13.5x2
where
x1 = length of service (years)
x2 = wage rate (dollars)
y = job satisfaction test score (higher scores indicate greater job satisfaction)
a. Interpret the coefficients in this estimated regression equation.
b. Predict the job satisfaction test score for an employee who has four years of service and makes $13.00 per hour.