a. True
b. false
2. If we are comparing two regression models, we usually prefer the one with the highest
adjusted RSquared value unless multicollinearity is a concern
a. True
b. false
3. Refer to the Orders tab. There is a statistically significant relationship at the 0.05 level
between orders and month.
a. True
b. false
4. There are no unusual x/y patterns (outliers) in the Orders data. There is a seasonal
pattern, but no outliers.
a. True
b. false
5. Refer to the Orders tab. For each additional month, orders decrease on average.
a. True
b. False
6. Refer to the Orders tab. The predicted number of orders increases by more than 0.5 per
period.
a. True
b. false
7. Refer to the Expenses tab. The plot of units sold vs. rainfall exhibits a negative
relationship.
a. True
b. false
8. Refer to the Expenses tab. Units sold and expenses are positively correlated.
a. True
b. false
9. Refer to the Expenses tab. This model exhibits severe multicollinearity.
a. True
b. false
10. Refer to the Expenses tab. The overall model explains more than half of the variation in
units sold.
a. True
b. false
11. Refer to the Expenses tab. The overall model is statistically insignificant at the 0.05
level.
a. True
b. false
12. Refer to the Expenses tab. Which variables are statistically significant predictors of units
sold at the 0.05 level?
a. Expenses
b. Number of employees only
c. Rainfall
d. More than one of the predictors are statistically significant.
13. Refer to the Expenses tab. If we delete an explanatory variable, the most appropriate
choice is
a. Expenses
b. Number of employees only
c. Rainfall
d. More than one of the predictors are statistically significant.
14. Refer to the Expenses tab. If we delete an explanatory variable, the most appropriate
choice is
a. Expenses
b. Number of employees only
c. Units sold
d. It depends on whether multicollinearity is a concern
15. Refer to the Expenses tab. Which explanatory variable appears to be the most useful
predictor in the presence of the other predictors?
a. Expenses
b. Rainfall
c. Number of employees
d. Intercept
16. Refer to the Expenses tab. If you were recommending use of this model, which of the
following would be most appropriate?
a. Years alone should be used to predict units sold.
b. We should use rainfall alone to predict units sold, as it is easily obtained data.
c. Expenses alone should be used to predict units sold, since we know the values
well in advance.
d. We cannot predict units sold, since demand is uncertain.
e. The choice of model will depend on whether multicollinearity is a concern.
17. Refer to the weight loss tab. The plot of weight loss vs. sessions shows a positive
relationship.
a. True
b. false
18. Refer to the weight loss tab. The overall model is statistically significant at the 0.05 level.
a. True
b. False
19. Refer to the weight loss tab. Used alone with loss, weight has a stronger linear
relationship than sessions.
a. True
b. False
20. Refer to the weight loss tab. When used together, weight and session both are
statistically significant predictors at the 0.10 level.
a. True
b. False
21. Refer to the weight loss tab. The intercept is negative. This means there is a flaw in the
model.
a. True
b. False
22. Refer to the weight loss tab. For each additional session attended, on average
participants lost fewer than 3 pounds holding beginning weight constant.
a. True
b. False
23. Refer to the weight loss tab. Some multicollinearity is present, but it is not severe.
a. True
b. False
24. Refer to the weight loss tab. If you were asked to draw an overall conclusion regarding
the weight loss data, which of the following would be best?
a. Attending 6 sessions is best, since the highest weight loss values occurred for
people attending 6 sessions.
b. Beginning weight is most important, since heavier people can lose more weight
than lighter ones.
c. For the best results, attend a s many sessions as possible.
d. This weight loss program is ineffective.
25. Of the 3 models given under the tabs, which had the lowest percentage of variation in y
explained by the model?
a. The model predicting units sold
b. The model predicting orders
c. The model predicting weight loss
d. No answer text provided
26. If there is no relationship between x and y, the slope will be negative.
a. True
b. false
27. If we are comparing two regression models, we usually prefer the one with the
highest standard error value unless multicollinearity is a concern.
a. True
b. False
28. Refer to the Orders tab. At least 15% of the variation in orders is explained using month
in the regression model
a. True
b. False
29. Refer to the Expenses tab. Units sold and expenses are negatively correlated.
a. True
b. False
30. Refer to the Expenses tab. The overall model explains less than half of the variation in
units sold.
a. True
b. False
31. Refer to the Expenses tab. The overall model explains less than half of the variation in
units sold.
a. True
b. False
32. Refer to the Expenses tab. The overall model is statistically insignificant at the 0.05
level.
a. True
b. False
33. Refer to the Rooms tab. The scatterplot contains at least one high-leverage case.
a. True
b. False
34. Refer to the Rooms tab. There is a significant positive relationship at the 0.05 level.
a. True
b. False
35. Refer to the Rooms tab. Which of the following statements is most appropriate?
a. The current data will generate a stronger fit is we omit an observation.
b. The current model is a strong predictor for future data.
c. This model is completely useless.
d. As more rooms are occupied, revenue declines
36. Of the four models presented, the one with the lowest standard error has the strongest
fit.
a. True
b. false