10 math problems

QUESTION 1

1. Which of the following is a true statement regarding correlation and causality?

   	A.	A high correlation always implies causality.
   	B.	A high correlation does not necessarily mean causality.
   	C.	Correlation and causality always go together.
   	D.	Correlation and causality never go together.

2 points   

QUESTION 2

1. If the correlation coefficient is r = .9, find the coefficient of determination r ².

   	A.	r 2 = .81 which is .92.
   	B.	r 2 is equal to r, which is .9.
   	C.	r 2 = 0 since r <1.
   	D.	r 2 = 1 since r is close to 1.

2 points   

QUESTION 3

1. Which value of r represents the strongest correlation?

   	A.	r = .95
   	B.	r = .74
   	C.	r = .89
   	D.	r = .65

2 points   

QUESTION 4

1. Which of the following represents no correlation?

   	A.	r = 0
   	B.	r = .2
   	C.	r = .9
   	D.	r = 1

2 points   

QUESTION 5

1. Match the following types of correlation with the properties of the regression line.

   -           A.           B.           C.       Negative Correlation          -           A.           B.           C.       Positive Correlation          -           A.           B.           C.       Perfect Correlation

   A. All of the data points lie on the regression line. B. The slope of the regression line is negative, decreasing from left to right. C. The slope of the regression line is positive, increasing from left to right.

2 points   

QUESTION 6

1. Which value of r represents the weakest correlation?

   	A.	r = .25
   	B.	r = .36
   	C.	r = .11
   	D.	r = .49

2 points   

QUESTION 7

1. Which of the following represents a perfect correlation?

   	A.	r = 0
   	B.	r = .3
   	C.	r = .8
   	D.	r = 1

2 points   

QUESTION 8

1. Match the following terms with their names.

   -           A.           B.           C.       Regression Equation          -           A.           B.           C.       Coefficient of Determination          -           A.           B.           C.       Correlation Coefficient

   A. r 2 B. y = a + bx C. r

2 points   

QUESTION 9

1. What would you conclude about the relationship between X and Y with a correlation coefficient of .85?

   	A.	The variables X and Y have a weak relationship since the correlation coefficient is not equal to 1.
   	B.	The variables X and Y have a strong relationship since the correlation coefficient is close to 1.
   	C.	The variables X and Y have no relationship since the correlation coefficient is less than 1.
   	D.	You can’t determine the strength of the relationship from the correlation coefficient.

2 points   

QUESTION 10

1. What would you conclude about the relationship between X and Y with a correlation coefficient of .14?

   	A.	The variables X and Y have a strong relationship since the correlation coefficient is close to 0.
   	B.	The variables X and Y have a strong relationship since the correlation coefficient is close to 1.
   	C.	The variables X and Y have a weak relationship since the correlation coefficient is close to 0.
   	D.	You can’t determine the strength of the relationship from the correlation coefficient.