Free SOA Exam SRM (Statistics for Risk Modeling) Linear Models Practice Questions
Linear models are the largest topic on SOA Exam SRM (SOA). Questions cover simple and multiple regression, generalized linear models (GLMs), regularization methods (ridge, LASSO, elastic net), and model diagnostics.
Sample Questions
The Pearson residual for observation in a GLM is defined as:
where is the variance function of the assumed distribution evaluated at the fitted mean. This standardizes the raw residual by the expected standard deviation under the model.
The systematic component of a GLM specifies the linear predictor, which is a linear combination of the predictors: . This determines how the covariates enter the model.
For OLS estimates to be unbiased, two conditions are essential: (1) the model must be correctly specified (the true relationship is linear in the parameters included), and (2) the errors have zero conditional mean, . This ensures . Unbiasedness does not require normality, homoscedasticity, or uncorrelated predictors.