Statistical Inferences Based on Two Samples

True/False

1. An independent sample experiment is an experiment in which there is no relationship between the measurements in the different samples. Answer: True Difficulty: Medium

2. When testing the difference between two proportions selected from populations with large independent samples, the Z test statistic is used. Answer: True Difficulty: Medium

3. In forming a large sample confidence interval for [pic], two assumptions are required: independent samples and sample sizes of at least 30. Answer: True Difficulty: Medium

4. In testing the equality of population variances, two assumptions are required: independent samples and normally distributed populations. Answer: True Difficulty: Medium

5. In an experiment involving matched pairs, a sample of 12 pairs of observations is collected. The degree of freedom for the t statistic is 10. Answer: False Difficulty: Medium

6. When comparing two independent population means, if n1 = 13 and n2 = 10, degrees of freedom for the t statistic is 22. Answer: False Difficulty: Easy

7. When comparing the variances of two normally distributed populations using independent random samples, if [pic], the calculated value of F will always be equal to one. Answer: True Difficulty: Easy

8. In testing the difference between two population variances, it is a common practice to compute the F statistic so that its value is always greater than or equal to one. Answer: True Difficulty: Medium

9. The F statistic can assume either a positive or a negative value. Answer: False Difficulty: Easy

10. There are two types of machines called type A and type B. Both type A and type B can be used to produce a certain product. The production manager wants to compare efficiency of the two machines. He assigns each of the fifteen workers to both types of machines to compare the hourly production rate of the 15 workers. In other words,...

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