Question 1

A sample of n = 9 scores has a variance of s² = 18.If the scores were a population,what value would be obtained for the population variance?

Accepted Answer

A)  ?2 = 14
B)  ?2 = 16
C)  ?2 = 24
D)  ?2 = 144 B

Question 2

For the following sample,use the computational formula to calculate SS and then compute the sample variance and standard deviation.Scores: 1,3,1,1

Accepted Answer

SS = 3,σ² = 1,and σ = 1

Question 3

Multiplying every score in a sample by 3 will not change the value of the standard deviation.

Accepted Answer

A) True 
 B)False  False

Question 4

A sample with SS = 40 and a variance of 8 has n = 5 scores.

Accepted Answer

A) True 
 B)False

Question 5

One sample is selected to represent scores in treatment 1 and a second sample is used to represent scores in treatment 2.Which set of sample statistics would present the clearest picture of a real difference between the two treatments?

Accepted Answer

A)  M1 = 36, M2 = 40, and both variances = 43
B)  M1 = 36, M2 = 40, and both variances = 6
C)  M1 = 38, M2 = 40, and both variances = 43
D)  M1 = 38, M2 = 40, and both variances = 6

Question 6

The sum of the squared deviation scores is SS = 20 for a sample of n = 5 scores.What is the variance for this sample?

Accepted Answer

A)  4
B)  5
C)  80
D)  100

Question 7

A researcher takes a sample from a population and computes a statistic for the sample.Which of the following statements is correct?

Accepted Answer

A)  If the sample statistic overestimates the corresponding population parameter, then the statistic is biased.
B)  If the sample statistic underestimates the corresponding population parameter, then the statistic is biased.
C)  If the sample statistic is equal to the corresponding population parameter, then the statistic is unbiased.
D)  None of the other statements is correct.

Question 8

Calculate the variance and the standard deviation for the following sample data.Scores: 1,0,3,1,2,4,0,1

Accepted Answer

The answer of Calculate the variance and the standard deviation...

Question 9

A sample of n = 7 scores has SS = 42.The variance for this sample is s² = 6.

Accepted Answer

A) True 
 B)False

Question 10

There is a 6-point difference between two sample means.If the two samples have the same variance,which of the following values would make the mean difference easiest to see in a graph showing the two distributions?

Accepted Answer

A)  s2 = 2
B)  s2 = 8
C)  s2 = 16
D)  s2 = 64

Question 11

A population of N = 100 scores has µ = 30 and σ = 4.What is the population variance?

Accepted Answer

A)  2
B)  4
C)  8
D)  16

Question 12

What is the value of SS (sum of squared deviations)for the following sample? Sample: 1,1,1,7

Accepted Answer

A)  52
B)  27
C)  25
D)  9

Question 13

Which of the following symbols identifies the population standard deviation?

Accepted Answer

A)  s
B)  s2
C)  ?
D)  ? 2

Question 14

Without some correction,sample variability is said to be "biased." Define the term biased,and explain how this bias is corrected in the formula for sample variance.

Accepted Answer

The answer of Without some correction,sample variability is said to...

Question 15

It is easier to see the mean difference between two samples if the sample variances are small.

Accepted Answer

A) True 
 B)False

Question 16

If the highest score in a distribution is X = 16 and the lowest is X = 4,then the range is 12 or 13 points.

Accepted Answer

A) True 
 B)False

Question 17

What is the value of SS for the following set of scores? Scores: 1,1,4,0

Accepted Answer

A)  18
B)  10
C)  9
D)  6

Question 18

A set of scores ranges from a high of X = 34 to a low of X = 24 and has a mean of 29.Which of the following is the most likely value for the standard deviation for these scores?

Accepted Answer

A)  2 points
B)  5 points
C)  10 points
D)  34 points

Question 19

Which of the following actions will have no effect on the value of the standard deviation?

Accepted Answer

A)  Multiply each score in the distribution by 2
B)  Divide each score in the distribution by 2
C)  Subtract 5 points from every score in the distribution
D)  All of the other actions will change the value of the standard deviation

Question 20

All the possible samples of n = 3 scores are selected from a population with µ = 30 and Ϭ = 5 and the mean is computed for each of the samples.If the average is calculated for all of the sample means,what value will be obtained?

Accepted Answer

A)  30
B)  Greater than 30
C)  Less than 30
D)  Impossible to predict

Exam 4: Variability.

A sample of n = 9 scores has a variance of s² = 18.If the scores were a population,what value would be obtained for the population variance?

For the following sample,use the computational formula to calculate SS and then compute the sample variance and standard deviation.Scores: 1,3,1,1

Multiplying every score in a sample by 3 will not change the value of the standard deviation.

A sample with SS = 40 and a variance of 8 has n = 5 scores.

One sample is selected to represent scores in treatment 1 and a second sample is used to represent scores in treatment 2.Which set of sample statistics would present the clearest picture of a real difference between the two treatments?

The sum of the squared deviation scores is SS = 20 for a sample of n = 5 scores.What is the variance for this sample?

A researcher takes a sample from a population and computes a statistic for the sample.Which of the following statements is correct?

Calculate the variance and the standard deviation for the following sample data.Scores: 1,0,3,1,2,4,0,1

A sample of n = 7 scores has SS = 42.The variance for this sample is s² = 6.

There is a 6-point difference between two sample means.If the two samples have the same variance,which of the following values would make the mean difference easiest to see in a graph showing the two distributions?

A population of N = 100 scores has µ = 30 and σ = 4.What is the population variance?

What is the value of SS (sum of squared deviations) for the following sample? Sample: 1,1,1,7

Which of the following symbols identifies the population standard deviation?

Without some correction,sample variability is said to be "biased." Define the term biased,and explain how this bias is corrected in the formula for sample variance.

It is easier to see the mean difference between two samples if the sample variances are small.

If the highest score in a distribution is X = 16 and the lowest is X = 4,then the range is 12 or 13 points.

What is the value of SS for the following set of scores? Scores: 1,1,4,0

A set of scores ranges from a high of X = 34 to a low of X = 24 and has a mean of 29.Which of the following is the most likely value for the standard deviation for these scores?

Which of the following actions will have no effect on the value of the standard deviation?

All the possible samples of n = 3 scores are selected from a population with µ = 30 and Ϭ = 5 and the mean is computed for each of the samples.If the average is calculated for all of the sample means,what value will be obtained?