Example 1. Simple Linear Regression: Service Calls Data

Discussion:

• Based upon the SAS plot of Y*X1, there does appear to be a linear relationship between the number of units and service time in minutes. It is evident from this plot that as the number of units repaired increases, the service time increases. The correlation between the number of units and service time in minutes is 0.9469, also indicating a strong positive correlation between the variables.
  
  
• Fitting a simple linear regression model relating service time (response) to units repaired (predictor), we find that the regression is hat(Y) = 37.213 + 9.9695*X1.