BUSN 4000 Exam 2 Questions and Answers Fully Solved Latest Update 2025-2026
Outliers - Answers Extreme Y value
How to detect: Standard residuals +-2
Leverage Points - Answers Extreme X value
How to detect: Highest leverage values from SmartREG
Influential Observations - Answers An observation that has a strong influence on the regression model
How to detect: Highest Cook's D or DFFITS
Model Assumptions - Answers 1. That the relationship is linear
2. That the variance is constant
3. That the errors/disturbances are normally distributed
Full F-Test input in excel - Answers F.DIST(k, n-k-1, F)
t-Test input in excel - Answers T.DIST(-t-stat, n-k-1, TRUE) x 2
Partial F-Test Statistic Calculation - Answers [(SSEreduced-SSEfull)/(k-l)]/MSEfull
k= number of variables in full model
l=number of variables in reduced model
Partial F-Test P-Value calculation - Answers F.DIST.RT(k-l, n-k-1 full, F-stat)
Multicollinearity - Answers Any VIF larger than 10 means there is collinearity present
Large F value, small t values
Prediction vs. Confidence intervals - Answers Prediction interval is ALWAYS wider than confidence
interval
This is because average or mean values are always more stable than individual values.
Confidence interval is for the prediction of an average/mean value, whereas prediction interval is for the
prediction of a single value.
Outliers - Answers Extreme Y value
How to detect: Standard residuals +-2
Leverage Points - Answers Extreme X value
How to detect: Highest leverage values from SmartREG
Influential Observations - Answers An observation that has a strong influence on the regression model
How to detect: Highest Cook's D or DFFITS
Model Assumptions - Answers 1. That the relationship is linear
2. That the variance is constant
3. That the errors/disturbances are normally distributed
Full F-Test input in excel - Answers F.DIST(k, n-k-1, F)
t-Test input in excel - Answers T.DIST(-t-stat, n-k-1, TRUE) x 2
Partial F-Test Statistic Calculation - Answers [(SSEreduced-SSEfull)/(k-l)]/MSEfull
k= number of variables in full model
l=number of variables in reduced model
Partial F-Test P-Value calculation - Answers F.DIST.RT(k-l, n-k-1 full, F-stat)
Multicollinearity - Answers Any VIF larger than 10 means there is collinearity present
Large F value, small t values
Prediction vs. Confidence intervals - Answers Prediction interval is ALWAYS wider than confidence
interval
This is because average or mean values are always more stable than individual values.
Confidence interval is for the prediction of an average/mean value, whereas prediction interval is for the
prediction of a single value.
