Question 1

It is possible to compute a correlation coefficient if we have

Accepted Answer

A)  a pair of scores for one individual 
B)  a set of scores for a group of individuals 
C)  two sets of scores for the same group of individuals 
D)  all of the above 
A)  a pair of scores for one individual 
B)  a set of scores for a group of individuals 
C)  two sets of scores for the same group of individuals 
D)  all of the above

Question 2

The correlation coefficient is obtained between academic aptitude test score and academic achievement (1) among students in general, and (2) among honor students. Other things being equal, we expect

Accepted Answer

A)  the two coefficients to be about the same 
B)  the first to be higher 
C)  the second to be higher 
D)  one to be negative, the other positive 
A)  the two coefficients to be about the same 
B)  the first to be higher 
C)  the second to be higher 
D)  one to be negative, the other positive

Question 3

Which of the following would be most likely to show a negative correlation?

Accepted Answer

A)  reaction time and skill as a driver 
B)  height and shoe size 
C)  hours studied and exam grade 
D)  weight of automobile and gas used per mile 
A)  reaction time and skill as a driver 
B)  height and shoe size 
C)  hours studied and exam grade 
D)  weight of automobile and gas used per mile

Question 4

The name of Spearman is associated with a coefficient of correlation obtained when scores are

Accepted Answer

A)  normally distributed 
B)  discrete variables 
C)  expressed as ranks 
D)  categorical 
A)  normally distributed 
B)  discrete variables 
C)  expressed as ranks 
D)  categorical

Question 5

A causal relationship between X and Y can be inferred

Accepted Answer

A)  only on grounds that go beyond the simple showing of a degree of relationship 
B)  any time r is other than zero 
C)  only for positive values of r 
D)  only for values of r that are near 1.00 
A)  only on grounds that go beyond the simple showing of a degree of relationship 
B)  any time r is other than zero 
C)  only for positive values of r 
D)  only for values of r that are near 1.00

Question 6

To begin calculating r

Accepted Answer

A)  the X scores should be put in order of magnitude 
B)  the X and Y scores should be put in order of magnitude 
C)  the pairs of X and Y scores may be in any order as long as the proper pairing is retained 
D)  any of the above procedures will be satisfactory 
A)  the X scores should be put in order of magnitude 
B)  the X and Y scores should be put in order of magnitude 
C)  the pairs of X and Y scores may be in any order as long as the proper pairing is retained 
D)  any of the above procedures will be satisfactory

Question 7

Dr. Jones wants to determine if there is any relationship between cigarette smoking and number of lectures missed due to illness in her graduate statistics course. She determines the number of cigarettes smoked per day and the number of classes missed for eight graduate students. The results are as follows: Calculate Pearson's r and construct a scatter diagram.

Accepted Answer

The answer of Dr. Jones wants to determine if there...

Question 8

Among a group of children, the correlation between test score in a science course and test score in an English course is +.45. It is learned that each test score is 5 points too high, so each raw score is corrected and r recomputed. We expect that its value will be

Accepted Answer

A)  greater than +.45 
B)  less than +.45 
C)  changed in an unpredictable way 
D)  unchanged 
A)  greater than +.45 
B)  less than +.45 
C)  changed in an unpredictable way 
D)  unchanged

Question 9

In the formula $\sum(X-\overline{X})(Y-\overline{Y})$ / nSXSY, the quantity that determines whether r will be negative or positive is

Accepted Answer

A)  n 
B)  $\sum(X-\overline{X})(Y-\overline{Y})$ 
C)    
D)  the combination of all these values 
A)  n 
B)  $\sum(X-\overline{X})(Y-\overline{Y})$ 
C)    
D)  the combination of all these values

Question 10

The human resources director for Company A often has lunch with the human resources director for Company B. This noon, she mentions that they are having trouble selecting good assembly workers. Her friend replies that they have had great luck with Aptitude Test X, and that the correlation, established on 400 of their assembly workers is +.60 between test score and job performance. Have you any caution to offer Company A's director before she rushes out to adopt the test as a selective device?

Accepted Answer

Yes; although both companies e

Question 11

Does a low r between two variables necessarily indicate there is very little association? Explain.

Accepted Answer

No; there could be a substantial curvili

Question 12

One teacher has a class composed entirely of girls; she finds that r between score on an English test and IQ is +.40 for her students. Another teacher has a class composed entirely of boys; she finds that r between score on an English test and IQ is +.55. Which of the following could not reasonably account for the discrepancy?

Accepted Answer

A)  the relationship is different among boys and girls 
B)  one teacher calculated r by the raw score method and the other by the deviation score method 
C)  the tests of English were different tests 
D)  variation is expected among samples 
A)  the relationship is different among boys and girls 
B)  one teacher calculated r by the raw score method and the other by the deviation score method 
C)  the tests of English were different tests 
D)  variation is expected among samples

Question 13

One hundred subjects are classified according to their standing in X and Y. The classification looks like this:

Accepted Answer

A)  r is large and positive 
B)  r is moderate and positive 
C)  r is zero 
D)  r is negative 
A)  r is large and positive 
B)  r is moderate and positive 
C)  r is zero 
D)  r is negative

Question 14

Four participants obtained the following scores on two measures. Compute r.

Accepted Answer

The answer of Four participants obtained the following scores on...

Question 15

The Spearman rank-order correlation coefficient

Accepted Answer

A)  is identical with Pearson r under all circumstances 
B)  is identical with Pearson r when both variables are in rank form and there are no ties in ranks 
C)  is identical with Pearson r when n is greater than 10 
D)  is never identical to Pearson r 
A)  is identical with Pearson r under all circumstances 
B)  is identical with Pearson r when both variables are in rank form and there are no ties in ranks 
C)  is identical with Pearson r when n is greater than 10 
D)  is never identical to Pearson r

Question 16

To study the phenomenon of creativity, a number of outstandingly creative persons are assembled and tested. It is found that rating on creativity and IQ correlate to the extent of 
   
 among this group. Does this necessarily indicate that creativity and intelligence have little to do with each other? Explain.

Accepted Answer

No; the range has been severel

Question 17

The correlation between score on a test of job aptitude and a measure of job proficiency is +.50 among 100 employed workers. The 25 workers who scored lowest in job proficiency and the 25 who scored highest are separated from the remainder, combined in one group, and the correlation between the same two variables is recomputed. We should expect it to be

Accepted Answer

A)  about the same as the first coefficient 
B)  higher than the first coefficient 
C)  lower than the first coefficient 
D)  different from the first coefficient, but we cannot predict whether higher or lower 
A)  about the same as the first coefficient 
B)  higher than the first coefficient 
C)  lower than the first coefficient 
D)  different from the first coefficient, but we cannot predict whether higher or lower

Question 18

Other things being equal, when the range of talent is reduced, r will

Accepted Answer

A)  increase 
B)  decrease 
C)  remain the same 
D)  change in an unpredictable manner 
A)  increase 
B)  decrease 
C)  remain the same 
D)  change in an unpredictable manner

It is possible to compute a correlation coefficient if we have

The correlation coefficient is obtained between academic aptitude test score and academic achievement (1) among students in general, and (2) among honor students. Other things being equal, we expect

Which of the following would be most likely to show a negative correlation?

The name of Spearman is associated with a coefficient of correlation obtained when scores are

A causal relationship between X and Y can be inferred

To begin calculating r

Among a group of children, the correlation between test score in a science course and test score in an English course is +.45. It is learned that each test score is 5 points too high, so each raw score is corrected and r recomputed. We expect that its value will be

In the formula $\sum(X-\overline{X})(Y-\overline{Y})$ / nS_XS_Y, the quantity that determines whether r will be negative or positive is

Does a low r between two variables necessarily indicate there is very little association? Explain.

One hundred subjects are classified according to their standing in X and Y. The classification looks like this:

Four participants obtained the following scores on two measures. Compute r.

The Spearman rank-order correlation coefficient

Other things being equal, when the range of talent is reduced, r will

Introduction

Frequency Distributions, Percentiles,

Graphic Representation of Frequency Distributions

Central Tendency

Variability and Standard Z Scores

Standard Scores and the Normal Curve

Prediction

Interpretive Aspects of Correlation and Regression

Probability

Random Sampling and Sampling Distributions

Introduction to Statistical Inference: Testing Hypotheses About Single Means Z and T

Interpreting the Results of Hypothesis Testing: Effect Size, Type I and Type II Errors, and Power

Testing Hypotheses About the Difference Between Two Independent Groups

Testing for a Difference

Inference About Correlation Coefficients

An Alternative to Hypothesis Testing: Confidence Intervals

Testing for Differences Among Three or More Groups: One-Way Analysis of Variance and Some Alternatives

Factorial Analysis of Variance

Chi-Square and Inference About Frequencies

Some Almost Assumption-Free Tests

Filters

Exam 7: Correlation

It is possible to compute a correlation coefficient if we have

The correlation coefficient is obtained between academic aptitude test score and academic achievement (1) among students in general, and (2) among honor students. Other things being equal, we expect

Which of the following would be most likely to show a negative correlation?

The name of Spearman is associated with a coefficient of correlation obtained when scores are

A causal relationship between X and Y can be inferred

To begin calculating r

Among a group of children, the correlation between test score in a science course and test score in an English course is +.45. It is learned that each test score is 5 points too high, so each raw score is corrected and r recomputed. We expect that its value will be

In the formula ∑(X−X‾)(Y−Y‾)\sum(X-\overline{X})(Y-\overline{Y})∑(X−X)(Y−Y) / nSXSY, the quantity that determines whether r will be negative or positive is

Does a low r between two variables necessarily indicate there is very little association? Explain.

One hundred subjects are classified according to their standing in X and Y. The classification looks like this:

Four participants obtained the following scores on two measures. Compute r.

The Spearman rank-order correlation coefficient

Other things being equal, when the range of talent is reduced, r will

Introduction

Frequency Distributions, Percentiles,

Graphic Representation of Frequency Distributions

Central Tendency

Variability and Standard Z Scores

Standard Scores and the Normal Curve

Prediction

Interpretive Aspects of Correlation and Regression

Probability

Random Sampling and Sampling Distributions

Introduction to Statistical Inference: Testing Hypotheses About Single Means Z and T

Interpreting the Results of Hypothesis Testing: Effect Size, Type I and Type II Errors, and Power

Testing Hypotheses About the Difference Between Two Independent Groups

Testing for a Difference

Inference About Correlation Coefficients

An Alternative to Hypothesis Testing: Confidence Intervals

Testing for Differences Among Three or More Groups: One-Way Analysis of Variance and Some Alternatives

Factorial Analysis of Variance

Chi-Square and Inference About Frequencies

Some Almost Assumption-Free Tests

Filters

In the formula $\sum(X-\overline{X})(Y-\overline{Y})$ / nS_XS_Y, the quantity that determines whether r will be negative or positive is