7.1 Mathematical Model

• The mean of \(Y\) values at any given \(X\) is \(\beta_{0} + \beta_{1} X\)
• The variance of \(Y\) values at any \(X\) is \(\sigma^2\) (same for all X)
  • This is known as homoscedasticity, or homogeneity of variance.
• \(Y\) values are normally distributed at any given \(X\) (need for inference)

Figure 6.2