Question 1

Which one of the following statistics indicates how much scores differ from each other?

Accepted Answer

A)   Mean
B)   Median
C)   Standard deviation
D)   Central tendency C

Question 2

Jim examines the effect of type of music (jazz,rock,rap)on task performance.Type of music represents which type of measurement scale?

Accepted Answer

A)   Ratio
B)   Interval
C)   Ordinal
D)   Nominal D

Question 3

Multiple correlation is a technique for

Accepted Answer

A)   increasing accuracy of prediction.
B)   multiplying correlation coefficients.
C)   making measures more reliable.
D)   determining causal relationships between variables. A

Question 4

Which one of the following would be an appropriate measure of central tendency to summarize ordinal data?

Accepted Answer

A)   Mean
B)   Median
C)   Correlation
D)   Mode

Question 5

What is the difference between an interval and a ratio scale? A ratio scale _____ while an interval scales does not.

Accepted Answer

A)   uses equal intervals
B)   has an absolute zero
C)   indicates order
D)   gives numerical information

Question 6

All correlation coefficients

Accepted Answer

A)   are positive.
B)   are negative.
C)   range from -1.00 to +1.00.
D)   use interval data.

Question 7

A teacher writes the results of a test on the board: 7 students received As,10 students received Bs,18 students received Cs,4 students received Ds,and 1 student received an F.In statistical terms,this is a

Accepted Answer

A)   measure of central tendency.
B)   measure of variability.
C)   frequency distribution.
D)   correlation table.

Question 8

In graphically depicting frequency distributions,_____ are used to display categorical variables while _____ are used to display quantitative variables.

Accepted Answer

A)   polygons;bar graphs
B)   bar graphs;histograms
C)   histograms;pie charts
D)   pie charts;bar graphs

Question 9

In a perfect relationship between two variables,r2

Accepted Answer

A)   would equal 0.
B)   would equal +1.00.
C)   would equal -1.00.
D)   would be less than the value of r.

Question 10

A common trick when bar graphs are used to mislead readers

Accepted Answer

A)   is to exaggerate the distance between points on the x axis
B)   is to exaggerate the distance between points on the y axis.
C)   is to use bright colours for the variable they want exaggerated.
D)   is to minimize the distance between points on the y axis.

Question 11

A researcher obtains a -.87 correlation between job applicants' ages and their likelihood to be hired,but she thinks job skills may be an important influence.She should calculate a(n)

Accepted Answer

A)   correlation coefficient between age and hiring likelihood.
B)   inter-rater reliability coefficient.
C)   partial correlation coefficient.
D)   regression equation.

Question 12

In a perfect positive relationship between two variables

Accepted Answer

A)   knowing an individual's score on one variable will allow us to predict exactly what his or her score will be on the other variable.
B)   the correlation coefficient would range between -1.0 and +1.0.
C)   all of the scores on one variable will be the same as the scores on the other variable.
D)   the graphic representation would be a flat line.

Question 13

The Pearson product-moment correlation coefficient (r)is unable to detect

Accepted Answer

A)   curvilinear relationships.
B)   positive linear relationships.
C)   negative linear relationships.
D)   instances of no relationship.

Question 14

Henry finds that for automobile owners,as the price of gasoline increases,the amount of miles they drive in a week decreases.This finding would suggest _____ relationship.

Accepted Answer

A)   a positive
B)   a negative
C)   a curvilinear
D)   no

Question 15

A regression equation is used to

Accepted Answer

A)   determine the strength of the relationship between X and Y.
B)   determine the causal relationship between X and Y.
C)   predict a score on Y from a known score on X.
D)   predict the difference between scores on X from the scores on Y.

Question 16

A correlation coefficient indicates the ________ and ________ of the relationship between two variables.

Accepted Answer

A)   nature;shape
B)   direction;strength
C)   scatter;strength
D)   direction;distribution

Question 17

A researcher finds that out of 400 pet owners surveyed,250 own only a dog,125 own only a cat,and 25 own only a bird.Which measure of central tendency is the most appropriate for this data?

Accepted Answer

A)   Mean
B)   Median
C)   Mode
D)   Standard deviation

Question 18

The correlation coefficient

Accepted Answer

A)   indicates the amount of spread in the distribution of scores.
B)   is a measure of central tendency.
C)   is a measure of variability.
D)   is a statistic that describes how strongly variables are related to one another.

Question 19

Mel finds the relationship between alcohol consumption and reaction time is -.63.However,the relationship between coffee consumption and reaction time is +.52.Mel can conclude

Accepted Answer

A)   the relationship between alcohol consumption and reaction time is weaker than the relationship between coffee consumption and reaction time.
B)   the relationship between alcohol consumption and reaction time is stronger than the relationship between coffee consumption and reaction time.
C)   the direction of the relationship between alcohol consumption and reaction time is approximately the same as the relationship between coffee consumption and reaction time.
D)   that alcohol consumption is directly related to coffee consumption.

Question 20

Why would a researcher employ structural modelling?

Accepted Answer

A)   It is the only appropriate statistical techniques to use when a third variable is present.
B)   It allows a researcher to test how well data fit a theoretical model that describes the relationship among variables.
C)   It allows the researcher to partial out the influence of a third variable.
D)   It is a more impressive statistical technique than correlation or regression.

Exam 12: Understanding Research Results: Describ-Ingvariables and Relationships Among Them