Question 1

In a follow-up study,a researcher reported that the correlation is .85.In the initial study,the correlation was .78.This means there is aan):
A)Stronger correlation between the variables in the follow-up study
B)Weaker correlation between the variables in the follow-up study
C)Unknown difference between the two studies
D)Error and the researcher should repeat the study

Accepted Answer

The correlation coefficient ranges from -1 to 1, with values closer to 1 indicating a stronger positive correlation. A change from .78 to .85 indicates an increase in the strength of the correlation between the variables in the follow-up study.

Question 2

A teacher reports that the class scores are generally distributed according to a bell curve.This means:
A)the mean,median,and mode have different values
B)the left half and the right half are not symmetrical
C)approximately 95% of the scores fall between -1 and +1 standard deviation from the mean
D)100% of the scores fall between -3 and +3 standard deviations from the mean

Accepted Answer

A bell curve, or normal distribution, is symmetric around the mean, implying that the mean, median, and mode are the same, which contradicts options A and B. Option C inaccurately states the percentage of scores within one standard deviation; approximately 68% of scores fall within this range, not 95%. Option D is correct because in a normal distribution, nearly all (about 99.7%) of the scores fall within three standard deviations from the mean.

Question 3

A teacher determines that the correlation between eating breakfast and doing well on the test is zero.This means:
A)a perfect correlation exists
B)there is an absence of a correlation
C)a negative correlation exists
D)the correlation cannot be determined

Accepted Answer

A correlation of zero means there is no linear relationship between the two variables, indicating an absence of correlation.

Question 4

A researcher wants to know if IQ predicts success in college.Which analysis is most appropriate?
A)Spearman's rho
B)Factor analysis
C)Regression
D)Pearson's Product Moment Correlation

Accepted Answer

Regression analysis is most appropriate for predicting one variable (success in college) based on another variable (IQ).

Question 5

The teacher calculates the highest score as being 97 and the lowest score as being 75.What is the range?
A)22
B)11
C)172
D)86

Accepted Answer

The range is the difference between the highest and lowest scores, which is 97 - 75 = 22.

Question 6

When comparing the four scales of measurement,what distinguishes the interval scale from the ratio scale?
A)Magnitude
B)Equal intervals
C)Absolute zero
D)There is no difference

Accepted Answer

The interval scale has equal intervals between measurements, but lacks an absolute zero point, which is a characteristic of the ratio scale. The ratio scale includes both equal intervals and an absolute zero, allowing for the calculation of ratios.

Question 7

A researcher determines that there is a positive correlation between sleep and test scores.This means as the amount of sleep is increased then test scores:
A)increase
B)decrease
C)remain the same
D)cannot be determined

Accepted Answer

A positive correlation means that as one variable increases, the other variable also increases. Therefore, if sleep increases, test scores also increase.

Question 8

A student conducting a research study was told by her professor to use a scatterplot in conjunction with calculating the correlation coefficient.She discovered that the data points clustered along a straight line.This means:
A)the student cannot determine if a relationship exists
B)no relationship exists between variables
C)a nonlinear relationship exists between variables
D)a linear relationship exists between variables

Accepted Answer

When data points cluster along a straight line in a scatterplot, it indicates a linear relationship between the variables. This means as one variable increases or decreases, the other variable tends to increase or decrease in a predictable manner. Calculating the correlation coefficient would further quantify the strength and direction of this linear relationship.

Question 9

The teacher has a small class with only 7 students.The teacher grades their homework and reports scores of: 10,7,8,12,9,11,and 13.What is the median?
A)10
B)70
C)35
D)15

Accepted Answer

The median is the middle number when the numbers are arranged in order. Arranging the scores (7, 8, 9, 10, 11, 12, 13), the median is 10.

Question 10

When looking at a list of students' test scores,the teacher notices that one test score is extremely lower than the majority of the scores.This is known as aan):
A)outer point
B)median
C)range
D)outlier

Accepted Answer

An outlier is a data point that is significantly different from the other data points in a dataset. In this case, the extremely low test score compared to the majority of scores is considered an outlier.

Question 11

If the researcher knows that the mean is 60 and the standard deviation is 6,then the majority of the scores falling between +1 or -1 standard deviation of the mean fall between:
A)60 and 66
B)54 and 60
C)54 and 66
D)Not enough information is provided

Accepted Answer

Scores falling within +1 or -1 standard deviation of the mean (60) would range from 60 - 6 = 54 to 60 + 6 = 66, thus encompassing options A and B together.

Question 12

In studying the correlation between the number of hours studied and scores on the comprehensive exam,the researcher found a correlation of .30.According to Cohen's guidelines,what would this mean regarding the strength of the relationship?
A)Large
B)Medium
C)Small
D)There is no guideline

Accepted Answer

The answer of In studying the correlation between the number...

Question 13

The teacher grades the papers and determines the following set of scores: 90,85,87,85,92,90,83,85,98 What is the mode?
A)92
B)85
C)98
D)83

Accepted Answer

The mode is the number that appears most frequently in a set of numbers. In this case, 85 appears three times, more than any other number, making it the mode.

Question 14

In comparing Spearman's Rho to Phi Coefficient,one would generally prefer to use Spearman's Rho when correlating:
A)Likert scale responses
B)Gender
C)Relationship status
D)Ratio scale variables

Accepted Answer

Spearman's Rho is preferred for correlating ordinal data, such as Likert scale responses, because it measures the strength and direction of association between two ranked variables.

Question 15

A researcher is looking for a specific study report,in which he knows the kurtosis value.He reads the following kurtosis value in various reports.Which one supports a mesokurtic distribution?
A)0
B)1
C)-1
D)Unknown

Accepted Answer

A mesokurtic distribution has a kurtosis value of 0, indicating a distribution shape that is similar to a normal distribution in terms of its tails and peak.

Question 16

A teacher analyzes the scores from a recent test and determines a positively skewed curve.She infers that the majority of students knew:
A)only a few of the answers due to low scores
B)most of the answers due to high scores
C)about half of the answers
D)an undetermined amount due to insufficient data

Accepted Answer

In a positively skewed distribution, most scores are low, with a few high scores pulling the mean to the right. This suggests that the majority of students scored lower, indicating they knew only a few of the answers.

Question 17

A research team designed a demographic questionnaire to collect information about participants.Which of the following variables identified on the questionnaire provides an example of an ordinal scale variable?
A)Age
B)Weight
C)Rank in the military
D)Relationship Status

Accepted Answer

Rank in the military is an example of an ordinal scale variable because it involves a ranking order where each rank is clearly defined but the intervals between the ranks are not necessarily equal or quantifiable.

Question 18

There are 12 participants who agree to take the test for a study focused on wellness.The total of all the participants' scores is 96.What is the mean?
A)84
B)8
C)1152
D)108

Accepted Answer

The mean score is calculated by dividing the total of all participants' scores by the number of participants. Here, 96 divided by 12 equals 8.

Question 19

The variance is determined to be 36.What would be the standard deviation?
A)6
B)18
C)9
D)Not enough information is provided

Accepted Answer

The standard deviation is the square root of the variance, so the square root of 36 is 6.

Question 20

A group of researchers is attempting to design an instrument that will measure self-esteem.The researchers have an extensive list of traits that may contribute to this construct.Which analysis may assist the research team in narrowing the list of traits into a few dimensions?
A)Spearman's rho
B)Factor analysis
C)Regression
D)Pearson's Product Moment Correlation

Accepted Answer

Factor analysis is used to identify underlying variables, or factors, that explain the pattern of correlations within a set of observed variables. This makes it suitable for narrowing down a large list of traits into a few dimensions by finding which traits cluster together based on their correlations.

Quiz 3: Statistical Concepts

In a follow-up study,a researcher reported that the correlation is .85.In the initial study,the correlation was .78.This means there is aan) :

A teacher reports that the class scores are generally distributed according to a bell curve.This means:

A teacher determines that the correlation between eating breakfast and doing well on the test is zero.This means:

A researcher wants to know if IQ predicts success in college.Which analysis is most appropriate?

The teacher calculates the highest score as being 97 and the lowest score as being 75.What is the range?

When comparing the four scales of measurement,what distinguishes the interval scale from the ratio scale?

A researcher determines that there is a positive correlation between sleep and test scores.This means as the amount of sleep is increased then test scores:

A student conducting a research study was told by her professor to use a scatterplot in conjunction with calculating the correlation coefficient.She discovered that the data points clustered along a straight line.This means:

The teacher has a small class with only 7 students.The teacher grades their homework and reports scores of: 10,7,8,12,9,11,and 13.What is the median?

When looking at a list of students' test scores,the teacher notices that one test score is extremely lower than the majority of the scores.This is known as aan) :

If the researcher knows that the mean is 60 and the standard deviation is 6,then the majority of the scores falling between +1 or -1 standard deviation of the mean fall between:

In studying the correlation between the number of hours studied and scores on the comprehensive exam,the researcher found a correlation of .30.According to Cohen's guidelines,what would this mean regarding the strength of the relationship?

The teacher grades the papers and determines the following set of scores: 90,85,87,85,92,90,83,85,98 What is the mode?

In comparing Spearman's Rho to Phi Coefficient,one would generally prefer to use Spearman's Rho when correlating:

A researcher is looking for a specific study report,in which he knows the kurtosis value.He reads the following kurtosis value in various reports.Which one supports a mesokurtic distribution?

A teacher analyzes the scores from a recent test and determines a positively skewed curve.She infers that the majority of students knew:

A research team designed a demographic questionnaire to collect information about participants.Which of the following variables identified on the questionnaire provides an example of an ordinal scale variable?

There are 12 participants who agree to take the test for a study focused on wellness.The total of all the participants' scores is 96.What is the mean?

The variance is determined to be 36.What would be the standard deviation?

A group of researchers is attempting to design an instrument that will measure self-esteem.The researchers have an extensive list of traits that may contribute to this construct.Which analysis may assist the research team in narrowing the list of traits into a few dimensions?