Question 1

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

Accepted Answer

A) True 
 B)False

Question 2

The advantage of squaring the deviation of each score from the mean and then summing is that

Accepted Answer

A) it makes the sample variance an unbiased estimator of the population variance 
B) it makes the degrees of freedom for sample variance equal to n - 1 
C) it produces a minimal positive solution that is not zero,so long as all scores are not exactly the same value 
D) both A and C 
A) it makes the sample variance an unbiased estimator of the population variance 
B) it makes the degrees of freedom for sample variance equal to n - 1 
C) it produces a minimal positive solution that is not zero,so long as all scores are not exactly the same value 
D) both A and C

Question 3

All other things being equal,how will the value of the sample variance be different from the population variance?

Accepted Answer

A) The sample variance will always be a smaller value than the population variance. 
B) The sample variance will always be a larger value than the population variance. 
C) The sample variance,but not the population variance,can be zero. 
D) The sample variance,but not the population variance,can be negative. 
A) The sample variance will always be a smaller value than the population variance. 
B) The sample variance will always be a larger value than the population variance. 
C) The sample variance,but not the population variance,can be zero. 
D) The sample variance,but not the population variance,can be negative.

Question 4

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 5

Suppose a researcher observes a population of 12 people and computes SS = 192.In this example,the standard deviation is 4.

Accepted Answer

A) True 
 B)False

Question 6

For a set of data that is normally distributed with 32±4 (M±SD),we know that 68% of the data will fall between scores of 28 and 36.

Accepted Answer

A) True 
 B)False

Question 7

The degrees of freedom for sample variance is equal to N.

Accepted Answer

A) True 
 B)False

Question 8

The SIQR can be defined as

Accepted Answer

A) the range of a distribution divided in half 
B) the IQR of a distribution plus the range 
C) a measure of half the distance between   And   
D) all of the above 
A) the range of a distribution divided in half 
B) the IQR of a distribution plus the range 
C) a measure of half the distance between   And   
D) all of the above

Question 9

Which of the following is true about the computational formula for variance?

Accepted Answer

A) The computational formula will always produce the same solution as the definitional formula (give or take rounding errors). 
B) It is a short-cut method for calculating variance when the population or sample size is large. 
C) It is derived mathematically from the definitional formula. 
D) all of the above 
A) The computational formula will always produce the same solution as the definitional formula (give or take rounding errors). 
B) It is a short-cut method for calculating variance when the population or sample size is large. 
C) It is derived mathematically from the definitional formula. 
D) all of the above

Question 10

Which of the following describes the definitional formula for variance?

Accepted Answer

A) It is stated in terms of how variance is defined. 
B) It is computed using SS in the numerator. 
C) It is a measure of the average squared distance that scores deviate from their mean. 
D) all of the above 
A) It is stated in terms of how variance is defined. 
B) It is computed using SS in the numerator. 
C) It is a measure of the average squared distance that scores deviate from their mean. 
D) all of the above

Question 11

A researcher computes the definitional formula for SS,as finds that ∑(x-M)= 44.If this is a sample of 12 scores,then what would the value of sample variance be using the computational formula?

Accepted Answer

A) 3.7 
B) 4.0 
C) 44 
D) not possible to know because the scores are not given 
A) 3.7 
B) 4.0 
C) 44 
D) not possible to know because the scores are not given

Question 12

The computational formula for the variance requires that you know the value of the mean.

Accepted Answer

A) True 
 B)False

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

If all scores in a distribution are negative values,then the standard deviation will also be a negative value.

Accepted Answer

A) True 
 B)False

Question 15

A researcher computes the definitional formula for SS,as finds that ∑(x-M)= 112.If this is a sample of 20 scores,then what would the value of population variance be using the computational 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 16

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

Question 17

A researcher measures the amount of coffee consumed by college students while studying during the final exam week.In her study,she found that students drink 2.3±0.8 (M±SD)cups of coffee per study session.Assuming the data are normally distributed,which of the following is the most appropriate conclusion?

Accepted Answer

A) The average student drinks less than 2.3 cups of coffee per study session. 
B) Most students drink between 1.5 and 3.1 cups of coffee per study session. 
C) Most students drink between 2.3 and 3.9 cups of coffee per study session. 
D) Most students drink between 0.7 and 2.3 cups of coffee per study session. 
A) The average student drinks less than 2.3 cups of coffee per study session. 
B) Most students drink between 1.5 and 3.1 cups of coffee per study session. 
C) Most students drink between 2.3 and 3.9 cups of coffee per study session. 
D) Most students drink between 0.7 and 2.3 cups of coffee per study session.

Question 18

Measures of variability can range in value from

Accepted Answer

A) - $\infty$ to + $\infty$ 
B) 0 to +   
C) It depends on whether the variability is positive or negative. 
D) It depends on the value of the mean for a given distribution. 
A) - $\infty$ to + $\infty$ 
B) 0 to +   
C) It depends on whether the variability is positive or negative. 
D) It depends on the value of the mean for a given distribution.

Question 19

On average,the sample variance equals the population variance only when dividing SS by df.

Accepted Answer

A) True 
 B)False

Question 20

Suppose a researcher selects a sample of 19 participants and computes SS = 162.In this example,the standard deviation is 3.

Accepted Answer

A) True 
 B)False

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

The advantage of squaring the deviation of each score from the mean and then summing is that

All other things being equal,how will the value of the sample variance be different from the population variance?

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

Suppose a researcher observes a population of 12 people and computes SS = 192.In this example,the standard deviation is 4.

For a set of data that is normally distributed with 32±4 (M±SD),we know that 68% of the data will fall between scores of 28 and 36.

The degrees of freedom for sample variance is equal to N.

The SIQR can be defined as

Which of the following is true about the computational formula for variance?

Which of the following describes the definitional formula for variance?

A researcher computes the definitional formula for SS,as finds that ∑(x-M)= 44.If this is a sample of 12 scores,then what would the value of sample variance be using the computational formula?

The computational formula for the variance requires that you know the value of the mean.

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

If all scores in a distribution are negative values,then the standard deviation will also be a negative value.

A researcher computes the definitional formula for SS,as finds that ∑(x-M)= 112.If this is a sample of 20 scores,then what would the value of population variance be using the computational formula?

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

Measures of variability can range in value from

On average,the sample variance equals the population variance only when dividing SS by df.

Suppose a researcher selects a sample of 19 participants and computes SS = 162.In this example,the standard deviation is 3.

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: Related Samples T Test

Estimation and Confidence Intervals

Analysis of Variance: One-Way Between-Subjects Design

Analysis of Variance: One-Way Within-Subjects Repeated Measures Design

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

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

The advantage of squaring the deviation of each score from the mean and then summing is that

All other things being equal,how will the value of the sample variance be different from the population variance?

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

Suppose a researcher observes a population of 12 people and computes SS = 192.In this example,the standard deviation is 4.

For a set of data that is normally distributed with 32±4 (M±SD),we know that 68% of the data will fall between scores of 28 and 36.

The degrees of freedom for sample variance is equal to N.

The SIQR can be defined as

Which of the following is true about the computational formula for variance?

Which of the following describes the definitional formula for variance?

A researcher computes the definitional formula for SS,as finds that ∑(x-M)= 44.If this is a sample of 12 scores,then what would the value of sample variance be using the computational formula?

The computational formula for the variance requires that you know the value of the mean.

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

If all scores in a distribution are negative values,then the standard deviation will also be a negative value.

A researcher computes the definitional formula for SS,as finds that ∑(x-M)= 112.If this is a sample of 20 scores,then what would the value of population variance be using the computational formula?

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

Measures of variability can range in value from

On average,the sample variance equals the population variance only when dividing SS by df.

Suppose a researcher selects a sample of 19 participants and computes SS = 162.In this example,the standard deviation is 3.

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: Related Samples T Test

Estimation and Confidence Intervals

Analysis of Variance: One-Way Between-Subjects Design

Analysis of Variance: One-Way Within-Subjects Repeated Measures Design

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