Deck 5: Ice Cream and Crime: Computing Correlation Coefficients

Question 1

What would you use to visually represent a correlation?

A)histogram
B)polygon
C)line graph
D)scatterplot

Answer 1

D

Question 2

If variables change in the opposite direction, what type of correlation is this called?

A)positive correlation
B)negative correlation
C)positive causation
D)negative causation

Answer 2

B

Question 3

If variables change in the same direction, what type of correlation is this called?

A)positive correlation
B)negative correlation
C)positive causation
D)negative causation

Answer 3

A

Question 4

Which of the following illustrates the range of possible values of Pearson's product-moment correlation coefficient?

A)-.01 to .01
B)-1.0 to 1.0
C)-2.0 to 2.0
D)-3.0 to 3.0

Question 5

Which of the following correlations would be interpreted as a very strong relationship?

A).80
B).70
C).60
D).50

Question 6

The Pearson correlation coefficient examines variables that are ______.

A)continuous in nature
B)not continuous in nature
C)categorical in nature
D)not categorical in nature

Question 7

Who is responsible for the invention of the Pearson product-moment correlation coefficient?

A)Pearson Fisher
B)Karl Pearson
C)Karl Fisher
D)Fisher Pearson

Question 8

If the correlation between variables is .80, what is the coefficient of determination?

A).20
B).34
C).64
D).80

Question 9

When data points group together in a cluster from the upper left-hand side of the xy axis to the lower right-hand side, what is this?

A)negative slope
B)positive slope
C)positive intercept
D)negative intercept

Question 10

When data points group together in a cluster from the lower left-hand side of the xy axis to the upper right-hand side, what is this?

A)negative slope
B)positive slope
C)negative intercept
D)positive intercept

Question 11

When interested in examining how one variable changes in relation to another, which of the following descriptive statistics would you want to use?

A)mean
B)variance
C)correlation
D)standard deviation

Question 12

A correlation coefficient is numerical index that reflects the relationship between ______>

A)one variable
B)two variables
C)three variables
D)a and b

Question 13

Correlation coefficients are used to describe ______.

A)a group
B)individuals
C)individuals as well as the group
D)this depends on the correlation coefficient used.

Question 14

Pearson's product-moment correlation coefficient is represented by the following letter:

A)r
B)p
C)c
D)z

Question 15

If the correlation between variables is .60, what is the coefficient of alienation?

A).36
B).40
C).60
D).64

Question 16

The correlation between variable X and variable Y is represented by which of the following?

A)R(xy)2
B)rₓᵧ
C)rx(y)
D)Rx / y

Question 17

Which of the following is an example of a correlation?

A)mean
B)variance
C)phi coefficient
D)standard deviation

Question 18

Which of the following refers to a correlation between two variables?

A)bicorrelate
B)bivariate
C)two-way variance
D)two-way analysis

Question 19

If the correlation between variables is .70, what percentage of the variance is shared variance?

A)70%
B)51%
C)49%
D)30%

Question 20

If the correlation between variables is .70, what percentage of the variance is not shared variance?

A)70%
B)51%
C)49%
D)30%

Question 21

The ______ is used to summarize the correlations between a set of variables:

A)scatterplot
B)correlation
C)correlation matrix
D)scatterplot matrix

Question 22

Which of the following is the weakest correlation?

A)-.24
B)-.22
C).19
D)-.96

Question 23

Which of the following correlations would be interpreted as a weak relationship?

A)-.26
B)-.46
C)-.66
D)-.86

Question 24

What type of correlation exist if the less time you take to complete a test, the more items you will get wrong?

A)positive correlation
B)negative correlation
C)indirect correlation
D)b & c

Question 25

If the range of one or both of the variables is restricted, the correlation will be _______.

A)strengthened
B)reduced
C)the same
D)It cannot be determined.

Question 26

The coefficient of determination is the percentage of variance in one variable that _________.

A)is accounted for by the variance in the other variable
B)matters only when the other variable is constant
C)equals the square root of the Pearson product-moment correlation coefficient
D)can be determined by taking the square root of the phi coefficient

Question 27

The amount of unexplained variance in a relationship between two variables is called _______.

A)coefficient of determination
B)coefficient of alienation
C)Pearson's product-moment correlation coefficient
D)phi coefficient

Question 28

Which of the following is the strongest correlation?

A).21
B).87
C).44
D)-.92

Question 29

Which of the following correlations would be interpreted a strong relationship?

A).39
B).59
C).79
D).89

Question 30

This is another word for a positive correlation.

A)inverse correlation
B)negative correlation
C)strong correlation
D)direct correlation

Question 31

What type of correlation exists if the more you exercise, the less you will weigh?

A)negative correlation
B)positive correlation
C)indirect correlation
D)a & c

Question 32

A positive correlation between two variables would be represented in a scatterplot as ______.

A)a line sloping upward
B)a line sloping downward
C)a horizontal line
D)a vertical line

Question 33

This is a situation in which the correlation between two variables begins as a direct correlation, then becomes an indirect correlation, or vice versa.

A)direct relationship
B)linear relationship
C)curvilinear relationship
D)reverse relationship

Question 34

This is a correlation that is best expressed as a straight line.

A)line correlation
B)direct correlation
C)strong correlation
D)linear correlation

Question 35

Which of the following correlations would be interpreted a moderate relationship?

A).25
B).35
C).45
D).65

Question 36

What type of correlation exists if the more time you spend studying, the higher your test score will be?

A)negative correlation
B)positive correlation
C)direct correlation
D)b & c

Question 37

If the correlation between two variables was equal to 0, the scatterplot between these two variables would be represented as ______.

A)a line sloping upward
B)a line sloping downward
C)a horizontal line
D)a vertical line

Question 38

A negative correlation between two variables would be represented in a scatterplot as ______.

A)a line sloping upward
B)a line sloping downward
C)a horizontal line
D)a vertical line

Question 39

What type of correlation exists if the less money you put in the bank, the less interest you will earn?

A)positive correlation
B)negative correlation
C)indirect correlation
D)none of the above

Question 40

This is another word for a negative correlation.

A)direct correlation
B)weak correlation
C)strong correlation
D)indirect correlation

Question 41

You can use Pearson's correlation coefficient if one or more of your variables are ordinal or nominal.

Question 42

This measure is equal to the percentage of variance in one variable that is accounted for by the variance in a second variable.

A)correlation coefficient
B)Pearson's product-moment correlation coefficient
C)coefficient of determination
D)coefficient of alienation

Question 43

The Pearson product-moment correlation examines the relationship between what type of variables?

A)discontinuous
B)continuous
C)nominal level
D)large

Question 44

"The better your time management skills are, the more work you are able to do" is an example of a _______.

A)continuous correlation
B)biserial correlation
C)positive correlation
D)negative correlation

Question 45

If we use Spearman rank coefficient correlation, what are the levels of measurement for both independent and dependent variables?

A)nominal and nominal
B)nominal and ordinal
C)ordinal and ordinal
D)interval and interval

Question 46

If X decreases in value as Y decreases, what type of correlation exists?

A)positive correlation
B)negative correlation
C)neutral correlation
D)no correlation

Question 47

A mediating variable is often called ______.

A)an independent variable
B)a dependent variable
C)a confounding variable
D)none of these

Question 48

If the coefficient of determination between two variables is .81, what is the Pearson correlation coefficient?

A).19
B).34
C).66
D).90

Question 49

When you have a direct correlation, both variables change in the same direction.

Question 50

If you wanted to compute the correlation between two nominal-level variables, which type of correlation should you use?

A)point biserial
B)phi
C)Spearman rank
D)Pearson

Question 51

If X decreases in value as Y increases in value, what type of correlation exists?

A)positive correlation
B)direct correlation
C)negative correlation
D)no correlation

Question 52

If you wanted to compute the correlation between two ordinal-level variables, which type of correlation should you use?

A)point biserial
B)phi
C)Spearman rank
D)Pearson

Question 53

What is the numerical index that describes the relationships between two variables?

A)regression coefficient
B)chi index
C)correlation coefficient
D)psi index

Question 54

If the coefficient of determination between two variables is .81, what is the coefficient of alienation?

A).19
B).34
C).66
D).90

Question 55

If X increases in value as Y increases, what type of correlation exists?

A)positive correlation
B)negative correlation
C)no correlation
D)inverse correlation

Question 56

If you wanted to compute the correlation between two interval-level variables, which type of correlation should you use?

A)Point biserial
B)Phi
C)Spearman rank
D)Pearson

Question 57

If you wanted to compute the correlation between one nominal-level variable and one interval-level variable, which type of correlation should you use?

A)point biserial
B)phi
C)Spearman rank
D)Pearson

Question 58

If X increases in value as Y decreases in value, what type of correlation exists?

A)positive
B)negative
C)neutral
D)none

Question 59

When testing partial correlation, the impact of a third variable is ______.

A)added
B)removed
C)deleted
D)reduced

Question 60

"The more oatmeal you eat, the lower your blood cholesterol level" is an example of a _______.

A)continuous correlation
B)biserial correlation
C)positive correlation
D)negative correlation

Question 61

Under what circumstances would you use the phi coefficient?

Question 62

How does a positive slope differ from a negative slope?

Question 63

Correlation coefficients describe every individual person in your data set.

Question 64

In a partial correlation, the impact of mediating variable is removed.

Question 65

In a correlation matrix, the numbers above and below the diagonal row of 1.00s are a mirror image of themselves.

Question 66

If two variables are correlated, this implies that one variable causes the other.

Question 67

In the formula for the Pearson correlation coefficient, what is the difference between the sum of a set of values squared and the sum of the squared values?

Question 68

How is a direct correlation different from an indirect correlation?

Question 69

It is better to find a positive correlation as opposed to a negative correlation.

Question 70

A correlation coefficient comparing exercise and body mass is -.67.What does this say about the relationship between exercise and weight?

Question 71

A negative correlation indicates that variables change in opposite directions.

Question 72

In certain cases, Pearson's product-moment correlation coefficient can have values greater than 1.

Question 73

Why will you rarely find a perfect correlation between any two variables?

Question 74

What is the purpose of a scatterplot?

Question 75

The coefficient of determination is more precise than using a correlation coefficient alone.

Question 76

Is a correlation of 0.6 stronger than a correlation of -0.9? Why or why not?

Question 77

A correlation coefficient comparing study time to grades is +.80.Can one then conclude that greater study time causes good grades? Why, or why not?