Share
Explore BrainMass

# understanding regression and correlation.

1. What is the variable used to predict the value of another called?
A) Independent
B) Dependent
C) Correlation
D) Determination

2. Based on the regression equation, we can
A) predict the value of the dependent variable given a value of the independent variable.
B) predict the value of the independent variable given a value of the dependent variable.
C) measure the association between two variables.

3. What is the range of values for a coefficient of correlation?
A) 0 to +1.0
B) -3 to +3 inclusive
C) -1.0 to +1.0 inclusive
D) Unlimited range

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

5. Which value of r indicates a stronger correlation than 0.40?
A) -0.30
B) -0.50
C) +0.38
D) 0

6. Suppose the least squares regression equation is Y' = 1202 + 1133X.
When X = 3, what does Y' equal?
A) 5,734
B) 8,000
C) 4,601
D) 4,050

7. In the least squares equation, Y' = 10 + 20X , the value of 20 indicates
A) the Y intercept.
B) for each unit increase in X, Y increases by 20.
C) for each unit increase in Y, X increases by 20.

8. In the equation Y' = a + bX, what is Y'?
A) Slope of the line
B) Y intercept
C) Predicted value of Y, given a specific X value
D) Value of Y when X=0

9. In the equation Y' = a + bX, what is a?
A) Slope of the line
B) Y intercept
C) Predicted value of Y, given a specific X value

10. 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

11. In the regression equation, y' = a + bx what does the letter "b" represent?
A) Y intercept
B) Slope of the line
C) Any value of the independent variable that is selected
D) Value of Y when X=0

12. A sales manager for an advertising agency believes there is a relationship between the number of contacts and the amount of the sales. What is the dependent variable?
A) Salesperson
B) Number of contacts
C) Amount of sales
D) All the above

#### Solution Preview

1. What is the variable used to predict the value of another called?
A) Independent
B) Dependent
C) Correlation
D) Determination
THE RIGHT HAND SIDE AND LEFT HAND SIDE VARIABLES HAVE ABOUT 7 NAMES FOR EACH BUT FROM THIS LIST WE CALL THE LEFT HAND SIDE VARIABLE THE DEPENDENT VARIABLE AND THE RIGHT HAND SIDE THE INDEPENDENT VARIABLE. THE INDEPENDENT VARIABLE IS USED TO PREDICT THE VALUE OF THE DEPENDENT VARIABLE.

2. Based on the regression equation, we can
A) predict the value of the dependent variable given a value of the independent variable.
B) predict the value of the independent variable given a value of the dependent variable.
C) measure the association between two variables.
I WOULD SAY (A) IS THE BEST ANSWER. ONCE WE ESTIMATE AN EQUATION WE CAN PLUG IN A VALUE FOR THE INDEPENDENT VARIABLE ON THE RIGHT HAND SIDE OF THE EQUATION AND USE THE EQUATION TO PREDICT A VALUE FOR THE DEPENDENT LEFT HAND SIDE VARIABLE. THAT SAID (C) IS A CLOSE SECOND ANSWER SINCE THE REGRESSION EQUATION WITH IT'S INTERCEPT AND SLOPE ESTIMATES ESTABLISHES AN ASSOCIATION AMONG THE VARIABLES AND ULTIMATELY ALLOWS US TO USE THE EQUATION FOR PREDICTIVE PURPOSES. I SUPPOSE IT IS BETTER TO SAY THAT GENERATING THE REGRESSION EQUATION ITSELF IS DONE BY A PROCESS THAT MEASURES THE ASSOCIATION BETWEEN VARIABLES BUT THE EQUATION ITSELF IS USED FOR ...

#### Solution Summary

The following provides a narrative on variables and parameters in regression analysis, uses of regression, and correlation. Numeric examples are provided as well.

\$2.19