Question 1

An interquartile range removes

Accepted Answer

A)  the top and bottom 25% of scores in a distribution before calculating range. 
B)  scores above only the 75th percentile before calculating range. 
C)  scores below only the 25th percentile before calculating range. 
D)  all of these. 
A)  the top and bottom 25% of scores in a distribution before calculating range. 
B)  scores above only the 75th percentile before calculating range. 
C)  scores below only the 25th percentile before calculating range. 
D)  all of these.

Question 2

The sample standard deviation is equal to 6 when SS = 360 and n = 11.

Accepted Answer

A) True 
 B)False

Question 3

A psychologist treats 16 patients and records the number of sessions required to complete a behavioral therapy treatment for each patient.She computes SS = 800.Assuming the 16 patients constitute all patients under her care (so the population of her patients),what is the standard deviation for these data?

Accepted Answer

A)  53.3 sessions 
B)  50 sessions 
C)  7.1 sessions 
D)  7.3 sessions 
A)  53.3 sessions 
B)  50 sessions 
C)  7.1 sessions 
D)  7.3 sessions

Question 4

One reason the denominator for sample variance is (n - 1)is because this makes it an unbiased estimator of the population variance.

Accepted Answer

A) True 
 B)False

Question 5

A researcher records the following data: 4,4,4,4,and 3.How would you describe the variability of these data?

Accepted Answer

A)  It is equal to zero because scores are approximately the same. 
B)  It is negative because 3 is less than the other scores in the distribution. 
C)  It is very small (close to 0) because scores are approximately the same. 
D)  It is very large (much greater than 0) because 3 is an outlier in the data. 
A)  It is equal to zero because scores are approximately the same. 
B)  It is negative because 3 is less than the other scores in the distribution. 
C)  It is very small (close to 0) because scores are approximately the same. 
D)  It is very large (much greater than 0) because 3 is an outlier in the data.

Question 6

A researcher computes the definitional formula for SS and finds that .If this is a sample of 20 scores,then what would the value of population variance be using the definitional formula?

Accepted Answer

A)  5.6 
B)  5.9 
C)  112 
D)  not possible to know because the scores are not given 
A)  5.6 
B)  5.9 
C)  112 
D)  not possible to know because the scores are not given

Question 7

Which of the following is consistent with the empirical rule?

Accepted Answer

A)  At least 68% of all scores lie within one standard deviation of the mean. 
B)  At least 95% of all scores lie within two standard deviations of the mean. 
C)  At least 99.7% of all scores lie within three standard deviations of the mean. 
D)  All of these. 
A)  At least 68% of all scores lie within one standard deviation of the mean. 
B)  At least 95% of all scores lie within two standard deviations of the mean. 
C)  At least 99.7% of all scores lie within three standard deviations of the mean. 
D)  All of these.

Question 8

The sample variance is an unbiased estimator of the population variance when dividing SS by df.

Accepted Answer

A) True 
 B)False

Question 9

Fractiles are ways that data can be divided into two or more equal parts.An example of a fractile includes

Accepted Answer

A)  the median. 
B)  quartiles. 
C)  percentiles. 
D)  all of these. 
A)  the median. 
B)  quartiles. 
C)  percentiles. 
D)  all of these.

Question 10

A researcher measures the number of trials it takes two samples of participants to master a new task.In both samples,SS = 240.Sample A consisted of 12 participants and Sample B consisted of 18 participants.Which sample is associated with the largest variance?

Accepted Answer

A)  Sample A 
B)  Sample B 
C)  Both samples have the same variance. 
D)  There is not enough information to answer this question. 
A)  Sample A 
B)  Sample B 
C)  Both samples have the same variance. 
D)  There is not enough information to answer this question.

Question 11

The 50th percentile is also called the median quartile.

Accepted Answer

A) True 
 B)False

Question 12

A researcher computes the following scores: 12,8,14,12,and 10.If these scores were substituted into each formula,the sample variance would be smaller than the population variance.

Accepted Answer

A) True 
 B)False

Question 13

How is the sample variance computed differently from the population variance?

Accepted Answer

A)  Only one formula includes a computation for SS. 
B)  The calculation in the numerator is different. 
C)  The calculation in the denominator is different. 
D)  None of these; the sample variance and population variance are computed the same. 
A)  Only one formula includes a computation for SS. 
B)  The calculation in the numerator is different. 
C)  The calculation in the denominator is different. 
D)  None of these; the sample variance and population variance are computed the same.

Question 14

If SS = 50 for a data set of 10 scores in a population,then the standard deviation is equal to 5.0.

Accepted Answer

A) True 
 B)False

Question 15

The range,a measure of variability,

Accepted Answer

A)  is the difference between the largest (L) and smallest (S) value in a list of scores. 
B)  is most informative when used to describe data sets without outliers. 
C)  includes only two values in its computation, regardless of the number of scores in a distribution. 
D)  all of these. 
A)  is the difference between the largest (L) and smallest (S) value in a list of scores. 
B)  is most informative when used to describe data sets without outliers. 
C)  includes only two values in its computation, regardless of the number of scores in a distribution. 
D)  all of these.

Question 16

The standard deviation is always positive or equal to 0.

Accepted Answer

A) True 
 B)False

Question 17

The degrees of freedom for the sample variance

Accepted Answer

A)  are equal to the sample size. 
B)  are equal to the sample size minus one. 
C)  can vary between -$\infty$ and +$\infty$. 
D)  are equal to the sample size minus one and can vary between -$\infty$ and +$\infty$. 
A)  are equal to the sample size. 
B)  are equal to the sample size minus one. 
C)  can vary between -$\infty$ and +$\infty$. 
D)  are equal to the sample size minus one and can vary between -$\infty$ and +$\infty$.

Question 18

Which of the following is a property of the standard deviation?

Accepted Answer

A)  The standard deviation varies between -$\infty$ and +$\infty$. 
B)  Adding the same constant to each score will change the standard deviation by that constant. 
C)  Multiplying each score times the same constant will change the standard deviation by that constant. 
D)  Both adding the same constant to each score will change the standard deviation by that constant and multiplying each score times the same constant will change the standard deviation by that constant. 
A)  The standard deviation varies between -$\infty$ and +$\infty$. 
B)  Adding the same constant to each score will change the standard deviation by that constant. 
C)  Multiplying each score times the same constant will change the standard deviation by that constant. 
D)  Both adding the same constant to each score will change the standard deviation by that constant and multiplying each score times the same constant will change the standard deviation by that constant.

Question 19

A measure of the average squared distance of scores from the mean is called the

Accepted Answer

A)  range. 
B)  IQR. 
C)  variance. 
D)  sum of squares. 
A)  range. 
B)  IQR. 
C)  variance. 
D)  sum of squares.

Question 20

Suppose a researcher observes a population of 25 people and computes SS = 360.In this example,the variance is 15.

Accepted Answer

A) True 
 B)False

An interquartile range removes

The sample standard deviation is equal to 6 when SS = 360 and n = 11.

One reason the denominator for sample variance is (n - 1)is because this makes it an unbiased estimator of the population variance.

A researcher records the following data: 4,4,4,4,and 3.How would you describe the variability of these data?

A researcher computes the definitional formula for SS and finds that .If this is a sample of 20 scores,then what would the value of population variance be using the definitional formula?

Which of the following is consistent with the empirical rule?

The sample variance is an unbiased estimator of the population variance when dividing SS by df.

Fractiles are ways that data can be divided into two or more equal parts.An example of a fractile includes

A researcher measures the number of trials it takes two samples of participants to master a new task.In both samples,SS = 240.Sample A consisted of 12 participants and Sample B consisted of 18 participants.Which sample is associated with the largest variance?

The 50th percentile is also called the median quartile.

A researcher computes the following scores: 12,8,14,12,and 10.If these scores were substituted into each formula,the sample variance would be smaller than the population variance.

How is the sample variance computed differently from the population variance?

If SS = 50 for a data set of 10 scores in a population,then the standard deviation is equal to 5.0.

The range,a measure of variability,

The standard deviation is always positive or equal to 0.

The degrees of freedom for the sample variance

Which of the following is a property of the standard deviation?

A measure of the average squared distance of scores from the mean is called the

Suppose a researcher observes a population of 25 people and computes SS = 360.In this example,the variance is 15.

Introduction to Statistics

Summarizing Data: Frequency Distributions in Tables and Graphs

Summarizing Data: Central Tendency

Probability

Probability, normal Distributions, and Z Scores

Probability and Sampling Distributions

Hypothesis Testing: Significance,effect Size,and Power

Testing Means: One-Sample and Two-Independent-Sample T Tests

Testing Means: Truehe Related-Samples T Test

Estimation and Confidence Intervals

Analysis of Variance: One-Way Between-Subjects Design

Analysis of Variance: One-Way Within-Subjects Repeated-Measuresdesign

Analysis of Variance: Two-Way Between-Subjects Factorial Design

Correlation

Linear Regression and Multiple Regression

Nonparametric Tests: Chi-Square Tests

Nonparametric Tests: Tests for Ordinal Data

Filters

Exam 4: Summarizing Data: Variability

An interquartile range removes

The sample standard deviation is equal to 6 when SS = 360 and n = 11.

One reason the denominator for sample variance is (n - 1)is because this makes it an unbiased estimator of the population variance.

A researcher records the following data: 4,4,4,4,and 3.How would you describe the variability of these data?

A researcher computes the definitional formula for SS and finds that .If this is a sample of 20 scores,then what would the value of population variance be using the definitional formula?

Which of the following is consistent with the empirical rule?

The sample variance is an unbiased estimator of the population variance when dividing SS by df.

Fractiles are ways that data can be divided into two or more equal parts.An example of a fractile includes

A researcher measures the number of trials it takes two samples of participants to master a new task.In both samples,SS = 240.Sample A consisted of 12 participants and Sample B consisted of 18 participants.Which sample is associated with the largest variance?

The 50th percentile is also called the median quartile.

A researcher computes the following scores: 12,8,14,12,and 10.If these scores were substituted into each formula,the sample variance would be smaller than the population variance.

How is the sample variance computed differently from the population variance?

If SS = 50 for a data set of 10 scores in a population,then the standard deviation is equal to 5.0.

The range,a measure of variability,

The standard deviation is always positive or equal to 0.

The degrees of freedom for the sample variance

Which of the following is a property of the standard deviation?

A measure of the average squared distance of scores from the mean is called the

Suppose a researcher observes a population of 25 people and computes SS = 360.In this example,the variance is 15.

Introduction to Statistics

Summarizing Data: Frequency Distributions in Tables and Graphs

Summarizing Data: Central Tendency

Probability

Probability, normal Distributions, and Z Scores

Probability and Sampling Distributions

Hypothesis Testing: Significance,effect Size,and Power

Testing Means: One-Sample and Two-Independent-Sample T Tests

Testing Means: Truehe Related-Samples T Test

Estimation and Confidence Intervals

Analysis of Variance: One-Way Between-Subjects Design

Analysis of Variance: One-Way Within-Subjects Repeated-Measuresdesign

Analysis of Variance: Two-Way Between-Subjects Factorial Design

Correlation

Linear Regression and Multiple Regression

Nonparametric Tests: Chi-Square Tests

Nonparametric Tests: Tests for Ordinal Data

Filters