Question 1

In the two sample case, the null hypothesis is always about the difference in the

Accepted Answer

The null hypothesis in a two sample test is always about the difference in the populations from which the two samples were drawn. The alternative hypothesis is typically that there is a difference between the populations. The standard errors and samples are used in calculating the test statistic and determining the p-value, but the null hypothesis statement itself is only about the populations.

Question 2

Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude?

Accepted Answer

Since the null hypothesis has been rejected, we can conclude that there is a significant difference between Republicans and Democrats in their level of support for welfare reform. Therefore, choice A is the correct option. Choice B is incorrect because it suggests that the parties are the same on this issue, which is not supported by the data. Choice C is also incorrect because the difference was found to be significant. Finally, choice D is not applicable here because there is no mention of a Type I error.

Question 3

Rejection of the null hypothesis in the two-sample case implies that the

Accepted Answer

Rejection of the null hypothesis in the two-sample case implies that there is a significant difference between the populations from which the samples are drawn on the trait of interest. Therefore, the best choice is B.

Question 4

When testing for the significance of the difference between two sample means, which parameters must be estimated with sample values?

Accepted Answer

The answer of When testing for the significance of the...

Question 5

For testing the difference between two sample means, the level of measurement is assumed to be

Accepted Answer

The level of measurement for testing the difference between two sample means is assumed to be interval-ratio. This is because the difference between two means requires the use of numerical values and the intervals between those values should be equal (i.e., interval-ratio data). Nominal and ordinal data do not provide enough information to accurately measure the difference between means.

Question 6

Random samples of men and women have been given a scale that measures their support for gun control. Men average 10.2 with standard deviation of 5.3. Women also average 10.2 but their standard deviation is 1.8. How could these results be dealt with appropriately?

Accepted Answer

The answer of Random samples of men and women have...

Question 7

When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using

Accepted Answer

The answer of When testing for the significance of the...

Question 8

When conducting hypothesis tests for two sample means, the test statistic is

Accepted Answer

The test statistic for hypothesis tests for two sample means is the difference in sample means, which is used to calculate the p-value and ultimately determine if there is a significant difference between the two populations. Alpha is the significance level chosen by the researcher, degrees of freedom are used in the calculation of the test statistic but are not the test statistic itself, and the difference in population means is unknown and what the researcher is attempting to determine.

Question 9

When testing for the significance of the difference between two samples, which is the proper assumption for step 1?

Accepted Answer

The proper assumption for step 1 when testing for the significance of the difference between two samples is that the samples are independent as well as random. This ensures that there is no systematic bias in the selection of samples and that the samples are not related to each other in any way. Random sampling (A) is also important, but it is already included in the assumption of independence. Ordinal level of measurement (B) is not relevant to the assumption for testing the difference between two samples. Degrees of freedom are calculated in step 3 and not assumed in step 1 (C is incorrect).

Question 10

When testing for the significance of the difference between two sample means, which of the following is almost always unknown?

Accepted Answer

The population standard deviations are almost always unknown when testing for the significance of the difference between two sample means. This is because in most cases, we do not have access to data on the entire population, and thus cannot calculate the population standard deviations. Instead, we rely on sample standard deviations to estimate the population standard deviations.

Question 11

A researcher conducted a survey to determine if older people have different feelings about abortion than younger people. He used an alpha level of 0.05 (Z critical = $\pm$1.96) to test for significance and found that his computed test statistic was 2.76. He may conclude that

Accepted Answer

The computed test statistic (2.76) is greater than the Z critical value (1.96). This means that the difference between the older and younger people's feelings about abortion did not occur by random chance and is statistically significant. Therefore, the researcher can reject the null hypothesis and conclude that there is a difference in feelings towards abortion between older and younger people.

Question 12

When conducting hypothesis tests for two sample means, the term $\mu$1 - $\mu$2 in the numerator of the formula reduces to zero because

Accepted Answer

The term F1F1F1S1F1F1F101 - F1F1F1S1F1F1F102 reduces to zero in the numerator of the formula when the null hypothesis is assumed to be true. This is because the null hypothesis assumes that the two sample means are equal, and therefore the difference between them (i.e. F1F1F1S1F1F1F101 - F1F1F1S1F1F1F102) should be zero.

Question 13

Samples of Republicans and Democrats have been tested for their level of support for a new immigration policy. The test statistic is 0.54 and the critical region begins at ± 1.96. What may we conclude?

Accepted Answer

The test statistic of 0.54 is not greater than the critical value of 1.96 or less than -1.96, so we fail to reject the null hypothesis. This means that we do not have enough evidence to suggest that there is a significant difference in the level of support for the new immigration policy between Republicans and Democrats.

Question 14

When testing for the significance of the difference between two sample means, we must first estimate ___________ before we can compute the test statistic.

Accepted Answer

The answer of When testing for the significance of the...

Question 15

When testing for the significance of the difference between two sample means, the null hypothesis can be stated as

Accepted Answer

The null hypothesis for testing the difference between two sample means is usually H0: µ1 = µ2, where µ1 and µ2 are the population means of two different groups. Choice C is the only option that is in this format.

Question 16

When random samples are drawn so that the selection of a case for one sample has no effect on the selection of cases for another sample, the samples are

Accepted Answer

When the selection of a case for one sample has no effect on the selection of cases for another sample, the samples are independent. This is a fundamental principle of statistics and is necessary for accurate and unbiased results. Dependent samples, in contrast, are those in which the selection of a case for one sample does have an effect on the selection of cases for another sample, and this can lead to biased or inaccurate results. Simple and systematic samples are types of sampling methods that are independent by design, but not all independent samples are necessarily simple or systematic.

Question 17

The central problem in the case of two-sample hypothesis test is to determine

Accepted Answer

The central problem in a two-sample hypothesis test is to determine if two populations differ significantly on the trait in question. The other choices (A, B, C) may be important considerations in conducting a hypothesis test, but they are not the central problem.

Question 18

To satisfy the requirement of independent random sampling, the researcher

Accepted Answer

Randomly selecting cases from one list of the population and then subdividing the sample according to the trait of interest is a way to ensure independent random sampling. This is because each case has an equal chance of being selected and the sample is not biased towards one specific sub-group of the population. Option A is incorrect because non-probability sampling does not ensure independent random sampling. Option C is incorrect because selecting members of families in a neighborhood may introduce bias if those families are not representative of the entire population. Option D is incorrect because selecting very small populations does not ensure that the sample is representative of the larger population.

Question 19

When testing for the significance of the difference between two samples, the null hypothesis states that the ____________ are the same

Accepted Answer

The null hypothesis in a two-sample hypothesis test is that the population means for the two samples are equal. The other answer choices are not applicable in this context.

Question 20

When testing for the significance of the difference between two sample means, the null hypothesis is that

Accepted Answer

The answer of When testing for the significance of the...

Quiz 8: Hypothesis Testing II the Two-Sample Case

In the two sample case, the null hypothesis is always about the difference in the

Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude?

Rejection of the null hypothesis in the two-sample case implies that the

When testing for the significance of the difference between two sample means, which parameters must be estimated with sample values?

For testing the difference between two sample means, the level of measurement is assumed to be

Random samples of men and women have been given a scale that measures their support for gun control. Men average 10.2 with standard deviation of 5.3. Women also average 10.2 but their standard deviation is 1.8. How could these results be dealt with appropriately?

When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using

When conducting hypothesis tests for two sample means, the test statistic is

When testing for the significance of the difference between two samples, which is the proper assumption for step 1?

When testing for the significance of the difference between two sample means, which of the following is almost always unknown?

A researcher conducted a survey to determine if older people have different feelings about abortion than younger people. He used an alpha level of 0.05 (Z critical = $\pm$ 1.96) to test for significance and found that his computed test statistic was 2.76. He may conclude that

When conducting hypothesis tests for two sample means, the term $\mu$ 1 - $\mu$ 2 in the numerator of the formula reduces to zero because

Samples of Republicans and Democrats have been tested for their level of support for a new immigration policy. The test statistic is 0.54 and the critical region begins at ± 1.96. What may we conclude?

When testing for the significance of the difference between two sample means, we must first estimate ___________ before we can compute the test statistic.

When testing for the significance of the difference between two sample means, the null hypothesis can be stated as

When random samples are drawn so that the selection of a case for one sample has no effect on the selection of cases for another sample, the samples are

The central problem in the case of two-sample hypothesis test is to determine

To satisfy the requirement of independent random sampling, the researcher

When testing for the significance of the difference between two samples, the null hypothesis states that the ____________ are the same

When testing for the significance of the difference between two sample means, the null hypothesis is that

Quiz 8: Hypothesis Testing II the Two-Sample Case

In the two sample case, the null hypothesis is always about the difference in the

Samples of Republicans and Democrats have been tested for their level of support for welfare reform and the null hypothesis has been rejected. What may we conclude?

Rejection of the null hypothesis in the two-sample case implies that the

When testing for the significance of the difference between two sample means, which parameters must be estimated with sample values?

For testing the difference between two sample means, the level of measurement is assumed to be

Random samples of men and women have been given a scale that measures their support for gun control. Men average 10.2 with standard deviation of 5.3. Women also average 10.2 but their standard deviation is 1.8. How could these results be dealt with appropriately?

When testing for the significance of the difference between two sample means, the standard deviation of the sampling distribution is estimated using

When conducting hypothesis tests for two sample means, the test statistic is

When testing for the significance of the difference between two samples, which is the proper assumption for step 1?

When testing for the significance of the difference between two sample means, which of the following is almost always unknown?

A researcher conducted a survey to determine if older people have different feelings about abortion than younger people. He used an alpha level of 0.05 (Z critical = ±\pm± 1.96) to test for significance and found that his computed test statistic was 2.76. He may conclude that

When conducting hypothesis tests for two sample means, the term μ\muμ 1 - μ\muμ 2 in the numerator of the formula reduces to zero because

Samples of Republicans and Democrats have been tested for their level of support for a new immigration policy. The test statistic is 0.54 and the critical region begins at ± 1.96. What may we conclude?

When testing for the significance of the difference between two sample means, we must first estimate ___________ before we can compute the test statistic.

When testing for the significance of the difference between two sample means, the null hypothesis can be stated as

When random samples are drawn so that the selection of a case for one sample has no effect on the selection of cases for another sample, the samples are

The central problem in the case of two-sample hypothesis test is to determine

To satisfy the requirement of independent random sampling, the researcher

When testing for the significance of the difference between two samples, the null hypothesis states that the ____________ are the same

When testing for the significance of the difference between two sample means, the null hypothesis is that

A researcher conducted a survey to determine if older people have different feelings about abortion than younger people. He used an alpha level of 0.05 (Z critical = $\pm$ 1.96) to test for significance and found that his computed test statistic was 2.76. He may conclude that

When conducting hypothesis tests for two sample means, the term $\mu$ 1 - $\mu$ 2 in the numerator of the formula reduces to zero because