Description
1. Short Essay (20 pts.) For each of these questions, your audience are persons that are not experts
in statistics. Write with complete sentences and paragraphs. Cite any references that you use.
a. (10 pts.) Imagine you fit a regression model to a dataset and find that R-squared = 0.69.
Is this a good regression model or not? If you cannot tell, what additional information do
you need? Explain.
b. (10 pts.) Research and then explain the “regression fallacy”. Provide at least one example.
2. QUASAR (30 pts.) — A quasar is a distant celestial object (at least four billion light-years away) that
provides a powerful source of radio energy. The Astronomical Journal (July 1995) reported on a
study of 90 quasars detected by a deep space survey. The survey enabled astronomers to measure
several different quantitative characteristics of each quasar, including:
X1 – Redshift
X2 – Line Flux
X3 – Line Luminosity
X4 – AB1450 Magnitude
X5 – Absolute Magnitude
Y1 – Rest frame Equivalent Width
a. (10 pts.) Use R to perform a regression analysis on the QUASAR dataset (found on the D2L).
For each of the explanatory variables create a regression model and copy/paste it into your
submission.
b. (10 pts.) Evaluate your models. For each discuss how well they predict the dependent
variable. Your description should begin by reporting basic facts about your model; but should
also include an analysis of the findings.
c. (10 pts.) Of the models you built, what is the “best” model? Explain. Assume your audience
is a fellow DSC423 student.
