Answers for all ‘Test Yourself’ questions from the book to check your performance and widen your overall understanding of the contents.

1.  
   
   1. Independent-samples t-test
   2. Chi-squared goodness-of-fit
   3. Regression
   4. One-way ANOVA
2. In a confirmatory approach, Clara would carefully consider how these variables might be related, forming specific research questions that she believed plausible and running appropriate statistical tests to address those questions.
3. The blank value is a missing value.  An “8” appears in the second variable, which is not a valid value for that variable.
4.  
   
   1. No; the appropriate analysis is regression, but department (the IV) is nominal.
   2. Yes; this is regression, and both variables are ratio-level
   3. No; department 6 months ago is not available in this dataset
   4. Yes; this is a one-sample t-test, and the age variable is ratio level
5. Much more influences stock price than just sales, and this was clearly not an experiment.  The report should not have concluded causation.  While sales and stock price might be associated, this is not necessarily causal.  The report also only surveyed the top 10 firms, so there may be range restriction in their dataset.