Question 1

In testing   vs.   the level of significance needs to be doubled before finding the critical value in the F table.

Accepted Answer

A) True 
 B)False

Question 2

The shape of the t distribution depends on the size of the sample because that influences the number of degrees of freedom.

Accepted Answer

A) True 
 B)False

Question 3

When small samples are used to estimate the true population mean where the population standard deviation is unknown, the standard normal distribution must be used to obtain the critical value.

Accepted Answer

A) True 
 B)False

Question 4

When comparing two population variances, we use the ratio   rather than the difference   .

Accepted Answer

A) True 
 B)False

Question 5

To test the difference between two population means by applying the two-sample procedure that uses a pooled estimate of the common variance   , the populations from which the samples are drawn must be t distributed.

Accepted Answer

A) True 
 B)False

Question 6

Which of the following correctly describes the term "degrees of freedom"?

Accepted Answer

A)  They are equal to the difference between the point estimate located at the interval centre and either the lower or the upper limit of the interval between which the parameter is free to move. 
B)  They determine the shape of the t distribution, and refer to the number of independent squared deviations inthat are available for estimatingand, in this sense, can be "freely chosen." 
C)  They equal sample size minus 2 in the case of a single sample. 
A)  They are equal to the difference between the point estimate located at the interval centre and either the lower or the upper limit of the interval between which the parameter is free to move. 
B)  They determine the shape of the t distribution, and refer to the number of independent squared deviations inthat are available for estimatingand, in this sense, can be "freely chosen." 
C)  They equal sample size minus 2 in the case of a single sample.

Question 7

A random sample of 25 observations is selected from a normally distributed population. The sample variance is 10. What is the upper limit of the 95% confidence interval for the population variance?

Accepted Answer

A)  6.097 
B)  17.110 
C)  17.331 
D)  19.353 
A)  6.097 
B)  17.110 
C)  17.331 
D)  19.353

Question 8

In testing for the equality of two population variances, when the populations are normally distributed, the 5% level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of 0.05.

Accepted Answer

A) True 
 B)False

Question 9

If two population variances have been tested and found to be equal, then it is reasonable to conclude that the two random samples selected from the two populations have equal variances.

Accepted Answer

A) True 
 B)False

Question 10

Variables that are F distributed range from 0 to   .

Accepted Answer

A) True 
 B)False

Question 11

Which of the following could be one possible reason for performing a paired-difference experiment?

Accepted Answer

A)  to reduce the degrees of freedom 
B)  to allow one to use a larger value of $\alpha$ 
C)  to reduce the quantity of information in the experiment 
D)  to reduce the variability in the sample data 
A)  to reduce the degrees of freedom 
B)  to allow one to use a larger value of $\alpha$ 
C)  to reduce the quantity of information in the experiment 
D)  to reduce the variability in the sample data

Question 12

In comparing two population means when samples are matched pairs, the variable under consideration is d, the difference between the corresponding sample values.

Accepted Answer

A) True 
 B)False

Question 13

The t distribution is symmetric about 0 but is more spread out than the standard normal distribution.

Accepted Answer

A) True 
 B)False

Question 14

The chi-square distribution can be used in constructing confidence intervals and carrying out hypothesis tests regarding the value of a population variance.

Accepted Answer

A) True 
 B)False

Question 15

The t distribution is used to construct a confidence interval for the population mean   when the population is unknown and the sample size is small.

Accepted Answer

A) True 
 B)False

Question 16

The value of F with area 0.05 to its right for   = 6 and   = 9 is 3.37.

Accepted Answer

A) True 
 B)False

Question 17

If a sample has 15 observations and a 90% confidence estimate for   is needed, the appropriate t score is 1.341.

Accepted Answer

A) True 
 B)False

Question 18

Which sampling distribution is used to make inferences about a single population variance?

Accepted Answer

A)  a normal distribution 
B)  a t distribution 
C)  an F distribution 
D)  a chi-square distribution 
A)  a normal distribution 
B)  a t distribution 
C)  an F distribution 
D)  a chi-square distribution

Question 19

A major department store chain is interested in estimating the average amount its credit card customers spent. Fifteen credit card accounts were randomly sampled and analyzed with the following results:   = $50.50 and   = 400. Assuming the distribution of the amount spent is approximately normal, what is the shape of the sampling distribution of the sample mean that will be used to create the desired confidence interval for   ?

Accepted Answer

A)  approximately normal with a mean of $50.50 
B)  a standard normal distribution 
C)  a t distribution with 15 degrees of freedom 
D)  a t distribution with 14 degrees of freedom 
A)  approximately normal with a mean of $50.50 
B)  a standard normal distribution 
C)  a t distribution with 15 degrees of freedom 
D)  a t distribution with 14 degrees of freedom

Question 20

The sample size in each independent sample must be the same if we are to test for differences between the means of two independent populations.

Accepted Answer

A) True 
 B)False

In testing vs. the level of significance needs to be doubled before finding the critical value in the F table.

The shape of the t distribution depends on the size of the sample because that influences the number of degrees of freedom.

When small samples are used to estimate the true population mean where the population standard deviation is unknown, the standard normal distribution must be used to obtain the critical value.

When comparing two population variances, we use the ratio rather than the difference .

To test the difference between two population means by applying the two-sample procedure that uses a pooled estimate of the common variance , the populations from which the samples are drawn must be t distributed.

Which of the following correctly describes the term "degrees of freedom"?

A random sample of 25 observations is selected from a normally distributed population. The sample variance is 10. What is the upper limit of the 95% confidence interval for the population variance?

In testing for the equality of two population variances, when the populations are normally distributed, the 5% level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of 0.05.

If two population variances have been tested and found to be equal, then it is reasonable to conclude that the two random samples selected from the two populations have equal variances.

Variables that are F distributed range from 0 to .

Which of the following could be one possible reason for performing a paired-difference experiment?

In comparing two population means when samples are matched pairs, the variable under consideration is d, the difference between the corresponding sample values.

The t distribution is symmetric about 0 but is more spread out than the standard normal distribution.

The chi-square distribution can be used in constructing confidence intervals and carrying out hypothesis tests regarding the value of a population variance.

The t distribution is used to construct a confidence interval for the population mean when the population is unknown and the sample size is small.

The value of F with area 0.05 to its right for = 6 and = 9 is 3.37.

If a sample has 15 observations and a 90% confidence estimate for is needed, the appropriate t score is 1.341.

Which sampling distribution is used to make inferences about a single population variance?

The sample size in each independent sample must be the same if we are to test for differences between the means of two independent populations.

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

A: probability and Probability Distributions

B: probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Estimation

A: large-Sample Tests of Hypotheses

B: large-Sample Tests of Hypotheses

B: Inference From Small Samples

A: The Analysis of Variance

B: The Analysis of Variance

A: linear Regression and Correlation

B: linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

A:nonparametric Statistics

B:nonparametric Statistics

Filters

Exam 10: A: Inference From Small Samples

In testing vs. the level of significance needs to be doubled before finding the critical value in the F table.

The shape of the t distribution depends on the size of the sample because that influences the number of degrees of freedom.

When small samples are used to estimate the true population mean where the population standard deviation is unknown, the standard normal distribution must be used to obtain the critical value.

When comparing two population variances, we use the ratio rather than the difference .

To test the difference between two population means by applying the two-sample procedure that uses a pooled estimate of the common variance , the populations from which the samples are drawn must be t distributed.

Which of the following correctly describes the term "degrees of freedom"?

A random sample of 25 observations is selected from a normally distributed population. The sample variance is 10. What is the upper limit of the 95% confidence interval for the population variance?

In testing for the equality of two population variances, when the populations are normally distributed, the 5% level of significance has been used. To determine the rejection region, it will be necessary to refer to the F table corresponding to an upper-tail area of 0.05.

If two population variances have been tested and found to be equal, then it is reasonable to conclude that the two random samples selected from the two populations have equal variances.

Variables that are F distributed range from 0 to .

Which of the following could be one possible reason for performing a paired-difference experiment?

In comparing two population means when samples are matched pairs, the variable under consideration is d, the difference between the corresponding sample values.

The t distribution is symmetric about 0 but is more spread out than the standard normal distribution.

The chi-square distribution can be used in constructing confidence intervals and carrying out hypothesis tests regarding the value of a population variance.

The t distribution is used to construct a confidence interval for the population mean when the population is unknown and the sample size is small.

The value of F with area 0.05 to its right for = 6 and = 9 is 3.37.

If a sample has 15 observations and a 90% confidence estimate for is needed, the appropriate t score is 1.341.

Which sampling distribution is used to make inferences about a single population variance?

The sample size in each independent sample must be the same if we are to test for differences between the means of two independent populations.

Describing Data With Graphs

Describing Data With Numerical Measures

Describing Bivariate Data

A: probability and Probability Distributions

B: probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Estimation

A: large-Sample Tests of Hypotheses

B: large-Sample Tests of Hypotheses

B: Inference From Small Samples

A: The Analysis of Variance

B: The Analysis of Variance

A: linear Regression and Correlation

B: linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

A:nonparametric Statistics

B:nonparametric Statistics

Filters