Question 1

Correlation and regression are related statistical functions. Which option best describes this relationship?

Accepted Answer

A)   Regression is a measure of how well correlation explains the relationship between two variables
B)   The correlation coefficient always lies on the regression line
C)   Correlation can indicate how well the regression line 'fits' the data
D)   The regression line can be calculated using values for the mean and the correlation coefficientE) C) and D)
F) A) and B)

Question 2

Which of the following statements is TRUE?

Accepted Answer

A)   Causality normally implies correlation
B)   Correlation normally implies causality
C)   There is never a relationship between causality and correlation
D)   Correlation only occurs when there is causalityE) A) and D)
F) B) and C)

Question 3

Data from established manufacturing companies in Morocco shows that the number of years' experience a sales person has is correlated with their average yearly sales. The correlation coefficient ( r)  is 0.62. Calculate, to 1 decimal place, the percentage of variation in sales that is accounted for by experience.

Accepted Answer

A)   62.0%
B)   61.6%
C)   45.3%
D)   38.4%E) B) and D)
F) B) and C)

Question 4

There is a positive correlation between two variables x and y. Which of the following statements is true?

Accepted Answer

A)   As x increases, y will increase
B)   As x increases, y will decrease
C)   As x increases, y will remain unchanged
D)   We cannot say what happens as x increasesE) A) and B)
F) A) and C) A

Question 5

Which of the following relationships would you expect to be negatively correlated?

Accepted Answer

A)   Marketing budget and Sales revenue
B)   Years of experience and Salary
C)   Volume of raw materials purchased and Unit cost
D)   Car speed and Stopping distanceE) B) and D)
F) B) and C)

Question 6

The analysis of two variables indicates a correlation with r = -0.85. Calculate, to 1 decimal place, the percentage of variation in the independent variable that is not accounted for by the dependent variable.

Accepted Answer

A)   85.0%
B)   72.3%
C)   56.3%
D)   27.8%E) A) and D)
F) All of the above

Question 7

Which of the following statements about rank correlation is NOT true?

Accepted Answer

A)   Rank correlation is sometimes used to approximate product moment correlation
B)   If one variable is non-numeric the rank correlation is most appropriate
C)   Rank correlation can be used if variables can be placed in order (e.g. of size) 
D)   Rank correlation is usually considered to be more accurate than product moment correlationE) A) and C)
F) B) and D)

Question 8

Which of the following options is not a valid value for the correlation coefficient?

Accepted Answer

A)   -0.94
B)   0
C)   0.36
D)   1.2E) B) and C)
F) A) and C) D

Question 9

What term is used to describe differences in the value of an independent variable which are accounted for by the y on x regression line?

Accepted Answer

A)   Correlated differences
B)   Explained differences
C)   Unexplained differences
D)   Regression differencesE) A) and D)
F) B) and D)

Question 10

Which of the following options gives the best definition of correlation?

Accepted Answer

A)   An estimate of strength of a relationship between two variables
B)   An estimate of the spread of values in a set of data
C)   An estimate of skewness in a set of data
D)   An estimate of causality between two variablesE) All of the above
F) C) and D) A

Exam 14: Correlation Techniques

Correlation and regression are related statistical functions. Which option best describes this relationship?

Correct Answer
verified

Which of the following statements is TRUE?

Correct Answer
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Correct Answer
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There is a positive correlation between two variables x and y. Which of the following statements is true?

Correct Answer
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A

Which of the following relationships would you expect to be negatively correlated?

Correct Answer
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The analysis of two variables indicates a correlation with r = -0.85. Calculate, to 1 decimal place, the percentage of variation in the independent variable that is not accounted for by the dependent variable.

Correct Answer
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Which of the following statements about rank correlation is NOT true?

Correct Answer
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Which of the following options is not a valid value for the correlation coefficient?

Correct Answer
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D

What term is used to describe differences in the value of an independent variable which are accounted for by the y on x regression line?

Correct Answer
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Which of the following options gives the best definition of correlation?

Correct Answer
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A

Exam 14: Correlation Techniques

Correlation and regression are related statistical functions. Which option best describes this relationship?

Correct AnswerverifiedShow Answer

Which of the following statements is TRUE?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

There is a positive correlation between two variables x and y. Which of the following statements is true?

Correct AnswerverifiedA

Which of the following relationships would you expect to be negatively correlated?

Correct AnswerverifiedShow Answer

The analysis of two variables indicates a correlation with r = -0.85. Calculate, to 1 decimal place, the percentage of variation in the independent variable that is not accounted for by the dependent variable.

Correct AnswerverifiedShow Answer

Which of the following statements about rank correlation is NOT true?

Correct AnswerverifiedShow Answer

Which of the following options is not a valid value for the correlation coefficient?

Correct AnswerverifiedD

What term is used to describe differences in the value of an independent variable which are accounted for by the y on x regression line?

Correct AnswerverifiedShow Answer

Which of the following options gives the best definition of correlation?

Correct AnswerverifiedA

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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A

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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D

Correct Answer
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Correct Answer
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A