1. If there is no relationship between x and y, the correlation coefficient will be negative

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