Questions from Applied Statistics

Q: (a). Generate a correlation matrix for your predictors. Round

(a). Generate a correlation matrix for your predictors. Round the results to three decimal places. (b). Based on the correlation matrix, is collinearity a problem?

Q: (a). If you did not already do so, rerun

(a). If you did not already do so, rerun the regression requesting variance inflation factors (VIFs) for your predictors. (b). Do the VIFs suggest that multicollinearity is a problem? Explain....

Q: (a). If you did not already do so, request

(a). If you did not already do so, request a table of standardized residuals. (b). Are any residuals outliers (three standard errors) or unusual (two standard errors)?

Q: If you did not already do so, request leverage statistics.

If you did not already do so, request leverage statistics. Are any observations influential? Explain.

Q: If you did not already do so, request a histogram of

If you did not already do so, request a histogram of standardized residuals and/or a normal probability plot. Do the residuals suggest non-normal errors? Explain.

Q: If you did not already do so, request a plot of

If you did not already do so, request a plot of residuals versus the fitted Y. Is heteroscedasticity a concern?

Q: Here are the ages of a random sample of 20 CEOs (

Here are the ages of a random sample of 20 CEOs (chief executive officers) of Fortune 500 U.S. corporations. (a). Find the mean, median, and mode. (b). Discuss advantages and disadvantages of each...

Q: If you are using time-series data, perform one or

If you are using time-series data, perform one or more tests for autocorrelation (visual inspection of residuals plotted against observation order, runs test, Durbin-Watson test). Is autocorrelation a...

Q: In a model of Ford’s quarterly revenue Total Revenue = β0 +

In a model of Ford’s quarterly revenue Total Revenue = β0 + β1 Car Sales + β2 Truck Sales + β3 SUVSales + ε, the three predictors are measured in number of units sold (not dollars). (a). Interpret ea...

Q: Which one of the following is true? Why not the others

Which one of the following is true? Why not the others? a. Histograms are useful for visualizing correlations. b. Pyramid charts are generally preferred to bar charts. c. A correlation coefficient ca...