Question 1

The chi-square value for a one-tailed (upper tail) hypothesis test at a 5% level of significance and a sample size of 25 is

Accepted Answer

A)  33.196. 
B)  36.415. 
C)  39.364. 
D)  37.652. 
A)  33.196. 
B)  36.415. 
C)  39.364. 
D)  37.652.

Question 2

A random sample of 31 sales charge showed a sample standard deviation of $50.A 90% confidence interval estimate of the population standard deviation is

Accepted Answer

A)  1715.101 to 4055.589. 
B)  1596.458 to 4466.679. 
C)  39.956 to 66.833. 
D)  41.393 to 63.684. 
A)  1715.101 to 4055.589. 
B)  1596.458 to 4466.679. 
C)  39.956 to 66.833. 
D)  41.393 to 63.684.

Question 3

The producer of a certain bottling equipment claims that the variance of all their filled bottles is .027 or less.A sample of 30 bottles showed a standard deviation of .2 ounces.The p-value for the test is

Accepted Answer

A)  between .025 to .05. 
B)  between .05 to .10. 
C)  .05. 
D)  .025. 
A)  between .025 to .05. 
B)  between .05 to .10. 
C)  .05. 
D)  .025.

Question 4

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.At the .05 level of significance, the null hypothesis

Accepted Answer

A)  should be rejected. 
B)  should not be rejected. 
C)  should be revised. 
D)  should not be tested. 
A)  should be rejected. 
B)  should not be rejected. 
C)  should be revised. 
D)  should not be tested.

Question 5

Based on the sample evidence below, we want to test the hypothesis that population A has a larger variance than population B. Sample A
Sample B
N
11
10
S2
12)1
5
​
The test statistic for this problem equals

Accepted Answer

A)  .4132. 
B)  1.1. 
C)  2.42. 
D)  2. 
A)  .4132. 
B)  1.1. 
C)  2.42. 
D)  2.

Question 6

Do the following sample data indicate that the variance of the population from which it has been drawn is significantly more than 17? Use α = .05.
X
12
5
9
14
10

Accepted Answer

Since χ² = 2.71 < 9.488 (p-va

Question 7

A sample of 31 observations yielded a sample variance of 16.If we want to test H0: σ2 = 16, the test statistic is

Accepted Answer

A)  20. 
B)  21. 
C)  30. 
D)  7.5. 
A)  20. 
B)  21. 
C)  30. 
D)  7.5.

Question 8

We are interested in testing whether the variance of a population is significantly less than 1.44.The null hypothesis for this test is

Accepted Answer

A)  H0: σ2 0: s2 ≥ 1.44. 
C)  H0: σ 0: σ2 ≥ 1.44. 
A)  H0: σ2 0: s2 ≥ 1.44. 
C)  H0: σ 0: σ2 ≥ 1.44.

Question 9

An egg packing company has stated that the standard deviation of the weights of their grade A large eggs is .07 ounces or less.The sample variance for 51 eggs was .0065 ounces.Can this sample result confirm the company's claim? Use α = .1.

Accepted Answer

Since χ² = 66.33 > 63.167 (p-

Question 10

​Consider the following hypothesis problem. n = 14
H0: σ2 a: σ2 > 410
​
At the 5% level of significance, the null hypothesis

Accepted Answer

A)  should be rejected​. 
B)  ​should not be rejected​. 
C)  ​should be revised. 
D)  should not be tested. 
A)  should be rejected​. 
B)  ​should not be rejected​. 
C)  ​should be revised. 
D)  should not be tested.

Question 11

​Consider the following hypothesis problem. n = 30
H0: σ2 = 500
S2 = 625
Ha: σ2 ≠ 500
​
​The test statistic equals

Accepted Answer

A)  ​23.20. 
B)  ​24.00. 
C)  ​36.25. 
D)  ​37.50. 
A)  ​23.20. 
B)  ​24.00. 
C)  ​36.25. 
D)  ​37.50.

Question 12

The chi-square value for a one-tailed (lower tail) test when the level of significance is .1 and the sample size is 15 is

Accepted Answer

A)  21.064. 
B)  23.685. 
C)  7.790. 
D)  6.571. 
A)  21.064. 
B)  23.685. 
C)  7.790. 
D)  6.571.

Question 13

The 90% confidence interval estimate of a population standard deviation when a sample variance of 50 is obtained from a sample of 15 items is

Accepted Answer

A)  26.8 to 124.356. 
B)  5.177 to 11.152. 
C)  5.436 to 10.321. 
D)  29.555 to 106.529. 
A)  26.8 to 124.356. 
B)  5.177 to 11.152. 
C)  5.436 to 10.321. 
D)  29.555 to 106.529.

Question 14

We are interested in testing whether the variance of a population is significantly more than 625.The null hypothesis for this test is

Accepted Answer

A)  H0: σ2 > 625. 
B)  H0: σ2 ≤ 625. 
C)  H0: σ2 ≥ 625. 
D)  H0: σ2 ≤ 25. 
A)  H0: σ2 > 625. 
B)  H0: σ2 ≤ 625. 
C)  H0: σ2 ≥ 625. 
D)  H0: σ2 ≤ 25.

Question 15

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit.A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit.Has there been a significant increase in the variance of the temperatures? Use α = .05.

Accepted Answer

Since χ² = 50.46 > 36.415 (p-va

Question 16

The sampling distribution of the ratio of independent sample variances extracted from two normal populations with equal variances is the

Accepted Answer

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

Question 17

​Consider the following sample information from Population A and Population B. ​
​
Sample A
Sample B
N
24
16
S2
32
38
​​
We want to test the hypothesis that the population variances are equal.At the 10% level of significance, the null hypothesis

Accepted Answer

A)  should be rejected. 
B)  ​should not be rejected. 
C)  ​should be revised. 
D)  should not be tested. 
A)  should be rejected. 
B)  ​should not be rejected. 
C)  ​should be revised. 
D)  should not be tested.

Question 18

For an F distribution, the number of degrees of freedom for the numerator

Accepted Answer

A)  must be larger than the number of degrees of freedom for the denominator. 
B)  must be smaller than the number of degrees of freedom for the denominator. 
C)  must be equal to the number of degrees of freedom for the denominator. 
D)  can be larger, smaller, or equal to the number of degrees of freedom for the denominator. 
A)  must be larger than the number of degrees of freedom for the denominator. 
B)  must be smaller than the number of degrees of freedom for the denominator. 
C)  must be equal to the number of degrees of freedom for the denominator. 
D)  can be larger, smaller, or equal to the number of degrees of freedom for the denominator.

Question 19

We are interested in determining whether or not the variances of the sales are equal for two small grocery stores.A sample of 16 days of sales at each store indicated the following.
Store A
Store B
n1 = 16
n2 = 16
s1 = $130
s2 = $100
​
Are the variances of the populations (from which these samples came) equal?
Use α = .05.

Accepted Answer

​
F = 1.69 < 2.86
p-value > .1

Question 20

A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces.A 95% confidence interval estimate of the variance for the population is

Accepted Answer

A)  .2313 to .8533. 
B)  .2224 to .7924. 
C)  .3042 to .5843. 
D)  .0925 to .3413. 
A)  .2313 to .8533. 
B)  .2224 to .7924. 
C)  .3042 to .5843. 
D)  .0925 to .3413.

The chi-square value for a one-tailed (upper tail) hypothesis test at a 5% level of significance and a sample size of 25 is

A random sample of 31 sales charge showed a sample standard deviation of $50.A 90% confidence interval estimate of the population standard deviation is

The producer of a certain bottling equipment claims that the variance of all their filled bottles is .027 or less.A sample of 30 bottles showed a standard deviation of .2 ounces.The p-value for the test is

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.At the .05 level of significance, the null hypothesis

Based on the sample evidence below, we want to test the hypothesis that population A has a larger variance than population B. Sample A Sample B N 11 10 S² 12)1 5 The test statistic for this problem equals

Do the following sample data indicate that the variance of the population from which it has been drawn is significantly more than 17? Use α = .05. X 12 5 9 14 10

A sample of 31 observations yielded a sample variance of 16.If we want to test H₀: σ² = 16, the test statistic is

We are interested in testing whether the variance of a population is significantly less than 1.44.The null hypothesis for this test is

An egg packing company has stated that the standard deviation of the weights of their grade A large eggs is .07 ounces or less.The sample variance for 51 eggs was .0065 ounces.Can this sample result confirm the company's claim? Use α = .1.

Consider the following hypothesis problem. n = 14 H₀: σ² < 410 S = 20 H_a: σ² > 410 At the 5% level of significance, the null hypothesis

Consider the following hypothesis problem. n = 30 H₀: σ² = 500 S² = 625 H_a: σ² ≠ 500 The test statistic equals

The chi-square value for a one-tailed (lower tail) test when the level of significance is .1 and the sample size is 15 is

The 90% confidence interval estimate of a population standard deviation when a sample variance of 50 is obtained from a sample of 15 items is

We are interested in testing whether the variance of a population is significantly more than 625.The null hypothesis for this test is

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit.A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit.Has there been a significant increase in the variance of the temperatures? Use α = .05.

The sampling distribution of the ratio of independent sample variances extracted from two normal populations with equal variances is the

Consider the following sample information from Population A and Population B. Sample A Sample B N 24 16 S² 32 38 We want to test the hypothesis that the population variances are equal.At the 10% level of significance, the null hypothesis

For an F distribution, the number of degrees of freedom for the numerator

A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces.A 95% confidence interval estimate of the variance for the population is

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Exam 11: Inferences About Population Variances

The chi-square value for a one-tailed (upper tail) hypothesis test at a 5% level of significance and a sample size of 25 is

A random sample of 31 sales charge showed a sample standard deviation of $50.A 90% confidence interval estimate of the population standard deviation is

The producer of a certain bottling equipment claims that the variance of all their filled bottles is .027 or less.A sample of 30 bottles showed a standard deviation of .2 ounces.The p-value for the test is

The contents of a sample of 26 cans of apple juice showed a standard deviation of .06 ounces.We are interested in testing whether the variance of the population is significantly more than .003.At the .05 level of significance, the null hypothesis

Based on the sample evidence below, we want to test the hypothesis that population A has a larger variance than population B. Sample A Sample B N 11 10 S2 12)1 5 ​ The test statistic for this problem equals

Do the following sample data indicate that the variance of the population from which it has been drawn is significantly more than 17? Use α = .05. X 12 5 9 14 10

A sample of 31 observations yielded a sample variance of 16.If we want to test H0: σ2 = 16, the test statistic is

We are interested in testing whether the variance of a population is significantly less than 1.44.The null hypothesis for this test is

An egg packing company has stated that the standard deviation of the weights of their grade A large eggs is .07 ounces or less.The sample variance for 51 eggs was .0065 ounces.Can this sample result confirm the company's claim? Use α = .1.

​Consider the following hypothesis problem. n = 14 H0: σ2 < 410 S = 20 Ha: σ2 > 410 ​ At the 5% level of significance, the null hypothesis

​Consider the following hypothesis problem. n = 30 H0: σ2 = 500 S2 = 625 Ha: σ2 ≠ 500 ​ ​The test statistic equals

The chi-square value for a one-tailed (lower tail) test when the level of significance is .1 and the sample size is 15 is

The 90% confidence interval estimate of a population standard deviation when a sample variance of 50 is obtained from a sample of 15 items is

We are interested in testing whether the variance of a population is significantly more than 625.The null hypothesis for this test is

The standard deviation of the daily temperatures in Honolulu last year was 4 degrees Fahrenheit.A random sample of 25 days resulted in a standard deviation of 5.8 degrees Fahrenheit.Has there been a significant increase in the variance of the temperatures? Use α = .05.

The sampling distribution of the ratio of independent sample variances extracted from two normal populations with equal variances is the

​Consider the following sample information from Population A and Population B. ​ ​ Sample A Sample B N 24 16 S2 32 38 ​​ We want to test the hypothesis that the population variances are equal.At the 10% level of significance, the null hypothesis

For an F distribution, the number of degrees of freedom for the numerator

A sample of 20 cans of tomato juice showed a standard deviation of .4 ounces.A 95% confidence interval estimate of the variance for the population is

Data and Statistics

Descriptive Statistics: Tabular and Graphical Displays

Descriptive Statistics: Numerical Measures

Introduction to Probability

Discrete Probability Distributions

Continuous Probability Distributions

Sampling and Sampling Distributions

Interval Estimation

Hypothesis Tests

Inference About Means and Proportions With Two Populations

Comparing Multiple Proportions, Tests of Independence and Goodness of Fit

Experimental Design and Analysis of Variance

Simple Linear Regression

Multiple Regression

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Based on the sample evidence below, we want to test the hypothesis that population A has a larger variance than population B. Sample A Sample B N 11 10 S² 12)1 5 The test statistic for this problem equals

A sample of 31 observations yielded a sample variance of 16.If we want to test H₀: σ² = 16, the test statistic is

Consider the following hypothesis problem. n = 14 H₀: σ² < 410 S = 20 H_a: σ² > 410 At the 5% level of significance, the null hypothesis

Consider the following hypothesis problem. n = 30 H₀: σ² = 500 S² = 625 H_a: σ² ≠ 500 The test statistic equals

Consider the following sample information from Population A and Population B. Sample A Sample B N 24 16 S² 32 38 We want to test the hypothesis that the population variances are equal.At the 10% level of significance, the null hypothesis