Test Bank – Essentials of Statistics for the
Behavioral Sciences, 15th Edition by
Frederick Gravetter | Complete Exam
Prep 2026|Highly Graded!!
Population - CORRECT ANSWERS-The entire group of individuals a researcher wishes
to study
Sample - CORRECT ANSWERS-A subset of the population that is intended to
represent, or stand in for the population
Random Sampling - CORRECT ANSWERS-Each member of the population has an
equal chance of being included in each level
Sampling Error - CORRECT ANSWERS-The naturally occurring discrepancy, or error,
that exists between a sample statistic and the corresponding population parameter
*Increase sample size
*Keep variability in each population relatively small
Statistics - CORRECT ANSWERS-Numerical values that are based on data from the
sample
*Symbols are letters from the English alphabet
Parameters - CORRECT ANSWERS-Numerical values that are based on the data from
an entire population
*Symbols for parameters are letters from the Greek alphabet
Independent Variable - CORRECT ANSWERS-(X): The variable that is changed or
manipulated by the researcher, or the variable we believe causes a change in the other
variable
Dependent Variable - CORRECT ANSWERS-(Y): The variable being observed or
measured to assess the effect of the treatment
Y in Regression analyses - CORRECT ANSWERS-(Y): The variable that is being
predicted in Regression analyses
Predictor Variable (x in regression analyses) - CORRECT ANSWERS-(X): The variable
from which predictions are made in Regression analyses
,Nominal Measurement - CORRECT ANSWERS-Using numbers and labels to
categorize observations, but do not make any quantitative distinctions between
observations.
Example: Type of phobia
Ordinal Measurement - CORRECT ANSWERS-Categories that are organized in an
ordered sequence (size or magnitude).
Example: Class standing
Interval Measurement - CORRECT ANSWERS-Ordered categories that have equal
differences between numbers-but with an arbitrary zero point.
Example: Temperature in F*
Ratio Measurement - CORRECT ANSWERS-An interval scale with an absolute zero
point.
Example: Annual income in dollars.
Between-Subjects Design - CORRECT ANSWERS-Values of the independent variable
are split up between participants
Within-Subjects Design - CORRECT ANSWERS-Participants receive all levels of the
independent variables
Positively Skewed - CORRECT ANSWERS-Mode is towards the lower (more negative
end) of the distribution. Mode is at the HIGHEST point.
Negatively Skewed - CORRECT ANSWERS-Mode is towards the higher (more positive
end) of the distribution.
Mode is at the HIGHEST point.
Deviation - CORRECT ANSWERS-The distance separating the score from the Mean
Measure of Central Tendency - CORRECT ANSWERS-A statistical measure to
determine a single score that defines the CENTER of the distribution.
What is the goal of Central Dendency? - CORRECT ANSWERS-The goal of central
tendency is to find the single score that is most typical or most representative of the
entire group.
What are the 3 types of Central Tendency? - CORRECT ANSWERS-*Mode
*Median
*Mean
,Variance - CORRECT ANSWERS-This equals the mean squared deviation, or the
average squared distance from the mean
Standard Deviation - CORRECT ANSWERS-The positive square root of the variance
and PROVIDES A MEASURE OF THE AVERAGE DISTANCE FROM THE MEAN.
What does a Standard Deviation of zero mean? - CORRECT ANSWERS-When the
Standard Deviation equals zero, it means that there is no variability in the scores.
*The higher the values of the Standard Deviation, the more variability there is,
everything else being equal.
Z-Score - CORRECT ANSWERS-The distance a raw score is from the mean when
measured in units of standard deviation.
What do Z-Scores do? - CORRECT ANSWERS-Z-Scores allow us to determine the raw
scores location in a distribution, it's relative and simple frequency, and its percentile
Important characteristics of z-Scores - CORRECT ANSWERS-*A z-Score of 0 is equal
to the Mean of the raw score
*A positive z-score indicates the raw score is greater then the mean, a negative z-score
indicates the raw score is less than the Mean
*The larger the absolute value of a z-score, the less frequently that raw score occurs
*The standard deviation and variance of a set of standard scores always equals 1.00
*Even though the measures of central tendency and variability will change when you
convert to standard scores, the shape of the distribution does not change
*68% of the scores in a normal distribution will be +/- 1 z-score
*95% of the scores in a normal distribution will be +/- 2 z-scores
Power - CORRECT ANSWERS-The probability that the test will correctly reject a false
Null hypothesis. That is, the power is the probability that the test will identify a treatment
effect if one really exists.
What is effect size? - CORRECT ANSWERS-provides a measurement of the absolute
magnitude of a treatment effect, independent of the size of the sample being used
One-Tailed Test - CORRECT ANSWERS-Directional tests. result in significantly more
power because it increases the critical region in one direction
Null Hypothesis - CORRECT ANSWERS-A Null Hypothesis states that in the general
population there is no change, difference, or relationship between the two variables
*Symbol for the Null Hypothesis = Ho
, What does the Null Hypothesis do? - CORRECT ANSWERS-*In the context of an
experiment, Ho predicts that the IV (treatment) has no effect on the DV (Scores) for the
population
*Provides a starting point for any statistical test
Alternate Hypothesis - CORRECT ANSWERS-The Alternate Hypothesis states that
there is a change, difference, or relationship for the general population
*H1
Pearson Correlation Coefficient - CORRECT ANSWERS-Measures the degree and the
direction of the linear relationship between two variables
*Correlations range from -1 to +1 and are represented by the symbol r
*The strength of the correlation coefficient is determined by how far r is from 0.
Positive Correlation - CORRECT ANSWERS-The two variables tend to change in the
same direction
*As the value of X increases, the value of Y also tends to increase
*As the value of X decreases, the value of Y also tends to decrease
Negative Correlation - CORRECT ANSWERS-The two variables tend to go in the
opposite directions
*As the value of X increases, the value of Y tend to decrease and vice versa
*This is an inverse relationship
Things to remember about correlation-IMPORTANT - CORRECT ANSWERS-
*Correlation DOES NOT imply causation!
*The correlation between X and Y could be coincidental
*A third variable could be the cause of the correlation between X and Y
Regression - CORRECT ANSWERS-Regression is the statistical technique for finding
the best-fitting straight line for a set of data
Y^=a + bX : known as the regression line
Y^=the predicted value of X
b = Slope of the regression line
a= Intercept (the predicted value of Y when X=0)
Nonlinear Relationships - CORRECT ANSWERS-Two relationships may be related but
not linear, in this case they will be curvilinear
When Independent Measures ANOVA is used - CORRECT ANSWERS-*The
independent variable is between-subjects in nature
*The independent variable has three or more levels
Between-Group Variability - CORRECT ANSWERS-The difference BETWEEN the
mean scores for the groups
Behavioral Sciences, 15th Edition by
Frederick Gravetter | Complete Exam
Prep 2026|Highly Graded!!
Population - CORRECT ANSWERS-The entire group of individuals a researcher wishes
to study
Sample - CORRECT ANSWERS-A subset of the population that is intended to
represent, or stand in for the population
Random Sampling - CORRECT ANSWERS-Each member of the population has an
equal chance of being included in each level
Sampling Error - CORRECT ANSWERS-The naturally occurring discrepancy, or error,
that exists between a sample statistic and the corresponding population parameter
*Increase sample size
*Keep variability in each population relatively small
Statistics - CORRECT ANSWERS-Numerical values that are based on data from the
sample
*Symbols are letters from the English alphabet
Parameters - CORRECT ANSWERS-Numerical values that are based on the data from
an entire population
*Symbols for parameters are letters from the Greek alphabet
Independent Variable - CORRECT ANSWERS-(X): The variable that is changed or
manipulated by the researcher, or the variable we believe causes a change in the other
variable
Dependent Variable - CORRECT ANSWERS-(Y): The variable being observed or
measured to assess the effect of the treatment
Y in Regression analyses - CORRECT ANSWERS-(Y): The variable that is being
predicted in Regression analyses
Predictor Variable (x in regression analyses) - CORRECT ANSWERS-(X): The variable
from which predictions are made in Regression analyses
,Nominal Measurement - CORRECT ANSWERS-Using numbers and labels to
categorize observations, but do not make any quantitative distinctions between
observations.
Example: Type of phobia
Ordinal Measurement - CORRECT ANSWERS-Categories that are organized in an
ordered sequence (size or magnitude).
Example: Class standing
Interval Measurement - CORRECT ANSWERS-Ordered categories that have equal
differences between numbers-but with an arbitrary zero point.
Example: Temperature in F*
Ratio Measurement - CORRECT ANSWERS-An interval scale with an absolute zero
point.
Example: Annual income in dollars.
Between-Subjects Design - CORRECT ANSWERS-Values of the independent variable
are split up between participants
Within-Subjects Design - CORRECT ANSWERS-Participants receive all levels of the
independent variables
Positively Skewed - CORRECT ANSWERS-Mode is towards the lower (more negative
end) of the distribution. Mode is at the HIGHEST point.
Negatively Skewed - CORRECT ANSWERS-Mode is towards the higher (more positive
end) of the distribution.
Mode is at the HIGHEST point.
Deviation - CORRECT ANSWERS-The distance separating the score from the Mean
Measure of Central Tendency - CORRECT ANSWERS-A statistical measure to
determine a single score that defines the CENTER of the distribution.
What is the goal of Central Dendency? - CORRECT ANSWERS-The goal of central
tendency is to find the single score that is most typical or most representative of the
entire group.
What are the 3 types of Central Tendency? - CORRECT ANSWERS-*Mode
*Median
*Mean
,Variance - CORRECT ANSWERS-This equals the mean squared deviation, or the
average squared distance from the mean
Standard Deviation - CORRECT ANSWERS-The positive square root of the variance
and PROVIDES A MEASURE OF THE AVERAGE DISTANCE FROM THE MEAN.
What does a Standard Deviation of zero mean? - CORRECT ANSWERS-When the
Standard Deviation equals zero, it means that there is no variability in the scores.
*The higher the values of the Standard Deviation, the more variability there is,
everything else being equal.
Z-Score - CORRECT ANSWERS-The distance a raw score is from the mean when
measured in units of standard deviation.
What do Z-Scores do? - CORRECT ANSWERS-Z-Scores allow us to determine the raw
scores location in a distribution, it's relative and simple frequency, and its percentile
Important characteristics of z-Scores - CORRECT ANSWERS-*A z-Score of 0 is equal
to the Mean of the raw score
*A positive z-score indicates the raw score is greater then the mean, a negative z-score
indicates the raw score is less than the Mean
*The larger the absolute value of a z-score, the less frequently that raw score occurs
*The standard deviation and variance of a set of standard scores always equals 1.00
*Even though the measures of central tendency and variability will change when you
convert to standard scores, the shape of the distribution does not change
*68% of the scores in a normal distribution will be +/- 1 z-score
*95% of the scores in a normal distribution will be +/- 2 z-scores
Power - CORRECT ANSWERS-The probability that the test will correctly reject a false
Null hypothesis. That is, the power is the probability that the test will identify a treatment
effect if one really exists.
What is effect size? - CORRECT ANSWERS-provides a measurement of the absolute
magnitude of a treatment effect, independent of the size of the sample being used
One-Tailed Test - CORRECT ANSWERS-Directional tests. result in significantly more
power because it increases the critical region in one direction
Null Hypothesis - CORRECT ANSWERS-A Null Hypothesis states that in the general
population there is no change, difference, or relationship between the two variables
*Symbol for the Null Hypothesis = Ho
, What does the Null Hypothesis do? - CORRECT ANSWERS-*In the context of an
experiment, Ho predicts that the IV (treatment) has no effect on the DV (Scores) for the
population
*Provides a starting point for any statistical test
Alternate Hypothesis - CORRECT ANSWERS-The Alternate Hypothesis states that
there is a change, difference, or relationship for the general population
*H1
Pearson Correlation Coefficient - CORRECT ANSWERS-Measures the degree and the
direction of the linear relationship between two variables
*Correlations range from -1 to +1 and are represented by the symbol r
*The strength of the correlation coefficient is determined by how far r is from 0.
Positive Correlation - CORRECT ANSWERS-The two variables tend to change in the
same direction
*As the value of X increases, the value of Y also tends to increase
*As the value of X decreases, the value of Y also tends to decrease
Negative Correlation - CORRECT ANSWERS-The two variables tend to go in the
opposite directions
*As the value of X increases, the value of Y tend to decrease and vice versa
*This is an inverse relationship
Things to remember about correlation-IMPORTANT - CORRECT ANSWERS-
*Correlation DOES NOT imply causation!
*The correlation between X and Y could be coincidental
*A third variable could be the cause of the correlation between X and Y
Regression - CORRECT ANSWERS-Regression is the statistical technique for finding
the best-fitting straight line for a set of data
Y^=a + bX : known as the regression line
Y^=the predicted value of X
b = Slope of the regression line
a= Intercept (the predicted value of Y when X=0)
Nonlinear Relationships - CORRECT ANSWERS-Two relationships may be related but
not linear, in this case they will be curvilinear
When Independent Measures ANOVA is used - CORRECT ANSWERS-*The
independent variable is between-subjects in nature
*The independent variable has three or more levels
Between-Group Variability - CORRECT ANSWERS-The difference BETWEEN the
mean scores for the groups
