28 MCQs In Statistics ...

T F 1. Correlation analysis is a group of statistical techniques used to measure the strength of the relationship (correlation) between two variables.
T F2. A t test is used to test the significance of the coefficient of correlation.
T F 3. One assumption underlying linear regression is that the Y values are statistically dependent. This means that in selecting a sample, the Y values chosen, for a particular X value, depend on the Y values for any other X value.
T F 4. One assumption underlying linear regression is that for each value of X there is a group of Y values that is normally distributed.
T F 5. Trying to predict weekly sales with a standard error of estimate of $1,955, we would conclude that 68 percent of the predictions would not be off more than $1,955, 95 percent would not be off by more $3,910, and 99.7 percent would not be off by more than $5,865.
T F 6. Explained variation equals total variation minus unexplained variation.
T F 7. In the ANOVA table for regression, the total degrees of freedom is the sum the regression and error degrees of freedom.
T F 8. In a regression ANOVA table, the standard error of the estimate can be computed as the square root of the error mean square.
 

9. What is the general form of the regression equation?
A) Y' = ab
B) Y' = a + bX
C) Y' = a - bX
D) Y' = abX
 

10. Which of the following are true assumptions underlying linear regression: 1) for each value of X,
there is a group of Y values which is normally distributed; 2) the means of these normal distributions of Y
values all lie on the straight line of regression; and/or 3) the standard deviations of these normal
distributions are equal?
A) Only (1) and (2)
B) Only (1) and (3)
C) Only (2) and (3)
D) All of them
 

Use the following to answer questions 11-16:
 

Given the following five points: (-2,0), (-1,0), (0,1), (1,1), and (2,3).
 

11. What is the slope of the line?
A) 0.0
B) 0.5
C) 0.6
D) 0.7
 

12. What is the Y intercept?
A) 0.0
B) 0.7
C) 1.0
D) 1.5
 

13. What is the standard error of the estimate?
A) 0
B) 0.135
C) 0.367
D) 0.606
 

14. What is the critical value necessary to determine a confidence interval for a 95% level of confidence?
A) 2.132
B) 2.353
C) 2.776
D) 3.182
 

15. What is the critical value necessary to determine a confidence interval for a 90% level of confidence?
A) 1.533
B) 1.638
C) 2.132
D) 2.353
 

16. If the regression equation is Y' = 2 - 0.4X, what is the value of Y' when X = -3?
A) 0.8
B) 3.2
C) -10.0
D) 14.0
 

Use the following to answer questions 17-28:
 

A sales manager for an advertising agency believes there is a relationship between the number of contacts and the amount of the sales. To verify this belief, the following data was collected:
Salesperson Number of Contacts Sales (in thousands)
1 14 24
2 12 14
3 20 28
4 16 30
5 46 80
6 23 30
7 48 90
8 50 85
9 55 120
10 50 110
 

17. What is the dependent variable?
A) Salesperson
B) Number of contacts
C) Amount of sales
D) All the above
 

18. What is the independent variable?
A) Salesperson
B) Number of contacts
C) Amount of sales
D) All the above
 

19. What is the Y-intercept of the linear equation?
A) -12.201
B) 2.1946
C) -2.1946
D) 12.201
 

20. What is the slope of the linear equation?
A) -12.201
B) 12.201
C) 2.1946
D) -2.1946
 

21. What is the value of the standard error of estimate?
A) 9.3104
B) 8.778
C) 8.328
D) 86.68
 

22. What is the value of the coefficient of correlation?
A) 0.6317
B) 0.9754
C) 0.9513
D) 9.3104
 

23. What is the value of the coefficient of determination?
A) 9.3104
B) 0.9754
C) 0.6319
D) 0.9513
 

24. The 95% confidence interval for 30 calls is
A) 55.8, 51.5
B) 51.4, 55.9
C) 46.7, 60.6
D) 31.1, 76.2
 

25. The 95% prediction interval for a particular person making 30 calls is
A) 55.8, 51.5
B) 51.4, 55.9
C) 46.7, 60.6
D) 31.1, 76.2
 

26. What is the regression equation?
A) Y' = 2.1946 - 12.201X
B) Y' = -12.201 + 2.1946X
C) Y' = 12.201 + 2.1946X
D) Y' = 2.1946 + 12.201X
 

27. The SS total is
A) 14249.
B) 13555.
C) 693.48.
D) 156.37.
 

28. The calculated F value is
A) 156.37.
B) 02.64.
C) 86.68.
D) 9.31.