Statistical Techniques In Business And Economics 16th Edition By Lind – Test Bank

Chapter 11 Two-Sample Tests of Hypothesis Answer Key

True / False Questions

1. If the null hypothesis states that there is no difference between the mean income of males and the mean income of females, then the test is one-tailed.

FALSE
The test is two-tailed because we did not specify which group would have the larger mean. Also, the test is two-tailed because the null hypothesis is stated as “no difference,” or H0: μ1 = μ2.

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-01 Test a hypothesis that two independent population means are equal; assuming that the population standard deviations are known and equal.
Topic: Two-Sample Tests of Hypothesis: Independent Samples

2. If the null hypothesis states that there is no difference between the mean net income of retail stores in Chicago and New York City, then the test is two-tailed.

TRUE

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-01 Test a hypothesis that two independent population means are equal; assuming that the population standard deviations are known and equal.
Topic: Two-Sample Tests of Hypothesis: Independent Samples

3. When the standard deviations are equal but unknown, a test for the differences between two population means has n – 1 degrees of freedom.

FALSE
The degrees of freedom in the two sample test of means is found by n1 + n1 – 2.

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-02 Test a hypothesis that two independent population means are equal; with unknown population standard deviations.
Topic: Comparing Population Means with Unknown Population Standard Deviations

4. If we are testing for the difference between two population means and assume that the two populations have equal but unknown standard deviations, the variances are pooled to compute the best estimated variance.

TRUE

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-02 Test a hypothesis that two independent population means are equal; with unknown population standard deviations.
Topic: Comparing Population Means with Unknown Population Standard Deviations

5. If we are testing for the difference between two population means and assume that the two populations have equal and unknown standard deviations, the degrees of freedom are computed as (n1)(n2) – 1.

FALSE
The degrees of freedom in the two sample test of means is found by n1 + n1 – 2.

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-02 Test a hypothesis that two independent population means are equal; with unknown population standard deviations.
Topic: Comparing Population Means with Unknown Population Standard Deviations

6. A statistics professor wants to compare grades in two different classes of the same course. This is an example of a paired sample.

FALSE
The professor must assume the two classes are independent and use the two-sample test of means.

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-04 Explain the difference between dependent and independent samples.
Topic: Comparing Dependent and Independent Samples

7. If we are testing for the difference between two population means, it is assumed that the sample observations from one population are independent of the sample observations from the other population.

TRUE

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-04 Explain the difference between dependent and independent samples.
Topic: Comparing Dependent and Independent Samples

8. When dependent samples are used to test for differences in the means, we compute paired differences.

TRUE

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-04 Explain the difference between dependent and independent samples.
Topic: Comparing Dependent and Independent Samples

9. If two dependent samples of size 20 are used to test the difference between the means, the degrees of freedom for a t-statistic are 19.

TRUE

AACSB: Communication
Accessibility: Keyboard Navigation
Blooms: Understand
Difficulty: 1 Easy
Learning Objective: 11-03 Test a hypothesis about the mean population difference between paired or dependent observations.
Topic: Two-Sample Tests of Hypothesis: Dependent Samples

10. When dependent samples are used to test for differences in the means, we pool the sample variances.

FALSE
When dependent samples are used to test for differences in means, the sample variances are not pooled. We compute the variance of the differences between the paired observations.