By: mdegal • 1 year ago
By: marcoavilez96 • 3 year ago
By: mariskavankan • 3 year ago
Some examples from this set of practice questions
1.
True or False? Normality of the predictors is an assumption of MLR
Answer: False
2.
What would happen if you were to attempt a statistical analysis without making any assumptions?
Answer: Your analysis would produce an infinite number of equally plausible results.
3.
True or False? The residual errors need to be statistically independent after accounting for the fitted regression model. However, the observations do not need to be independent.
Answer: True
4.
Why is analyzing uncertainty an important part of statistics?
Answer: Because statisticians must be able to objectively quantify confidence in their conclusions.
5.
Why are the predictor variables usually assumed to be fixed in multiple linear regression?
Answer: Because multiple linear regression is a model of the conditional mean response, and explicitly modeling the predictors’ distribution does not help model the mean response. Moreover, explicitly modeling the predictors’ distribution would substantial increase the computationally complexity of regression modeling.
6.
True or False? When using multiple linear regression, the errors must be uncorrelated with the predictors.
Answer: True
7.
Why do we need to make assumptions when doing statistical analyses?
Answer: Data, by themselves, do not offer enough information to support statistical inference. We need to assume some properties of the population model that generated the data.
8.
What does the Gauss-Markov Theorem state?
Answer: The Gauss-Markov theorem states that if your linear regression model satisfies the first six classical assumptions, then ordinary least squares (OLS) regression produces unbiased estimates that have the smallest variance of all possible linear estimators.
9.
Why do we need the assumption of constant error variance in multiple linear regression?
Answer: Because multiple linear regression only models the mean response; we do not explicitly model the error variance.
10.
What is the most important consequence of violating the constant, finite error variance assumption?
Answer: The standard errors will be biased.
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Stuvia is a marketplace, so you are not buying this document from us, but from seller dc070498. Stuvia facilitates payment to the seller.
No, you only buy these notes for $4.38. You're not tied to anything after your purchase.
4.6 stars on Google & Trustpilot (+1000 reviews)
101808 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now
