Consider a multiple regression model designed to predict the annual salary of employees based on their years of experience, education level, and age. The model can be expressed as:
$$ ext{Salary} = \beta_0 + \beta_1 \times \text{Experience} + \beta_2 \times \text{Education} + \beta_3 \times \text{Age} + \epsilon $$
Where:
The researchers conducting this analysis assume the following characteristics about the error term $$ \epsilon $$:
Which of the following statements best describes a violation of these regression assumptions?