then you can compare the two services using simultaneous equations. Based on the answer you get, you’ll know to use Service A for any packages smaller than that, and Service B for any packages ...

The unknowns of \(x\) and \(y\) have the same value in both equations. This fact can be used to help solve the two simultaneous equations at the same time and find the values of \(x\) and \(y\).

Seemingly unrelated regression (SUR), also called joint generalized least squares (JGLS) or Zellner estimation, is a generalization of OLS for multi-equation systems. Like OLS, the SUR method assumes ...