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MANE 6313

Week 12, Module B

Student Learning Outcome

  • Select an appropriate experimental design with one or more factors,
  • Select an appropriate model with one or more factors,
  • Evaluate statistical analyses of experimental designs,
  • Assess the model adequacy of any experimental design, and
  • Interpret model results.

Module Learning Outcome

Analyzing linear regression models.

Resources for the Week 12, Module B micro-lecture are:


Fitting Linear Regression Models

Model Assumptions and Residuals

  • Least squares estimation requires that \(E(\mathbf{\varepsilon})=0\) and \(V(\mathbf{\varepsilon})=\sigma^2\) and the \(\left\{\mathbf{\varepsilon}_i\right\}\) are uncorrelated

  • To perform statistical hypothesis tests, we further assume that \(\mathbf{\varepsilon}\sim \mbox{NID}(0,\sigma^2)\)

  • These assumptions are validated by examining the residuals


Test for Significance of Regression

  • Test for significance of regression is a test to determine if there is a linear relationship between \(y\) and a subset of the regressors
\[ \begin{aligned} H_0:\beta_1&=&\beta_2=\cdots=\beta_k=0\\ H_a:\beta_j&\neq& 0 \mbox{ for at least one }j\end{aligned} \]
  • The test statistic is
\[ F_0=\frac{SS_R/k}{SS_E/(n-k-1)}=\frac{MS_R}{MS_E} \]
  • Reject \(H_0\) if \(F_0>F_{\alpha,k,n-k-1}\)

Minitab Demonstration