Question 1

Which of the following statements is true of a null hypothesis?

Accepted Answer

The null hypothesis typically states that there is no significant difference between two groups or treatments. In this case, the null hypothesis states that there is no significant difference between the means of the placebo treatment group and the experimental treatment group. Therefore, choice D is the only statement that accurately reflects a null hypothesis.

Question 2

A researcher was interested in the differences in the opinions about marriage between men and women. She predicted that women would have different opinions about marriage from men. What would the null hypothesis suggest in this situation?

Accepted Answer

The null hypothesis always suggests that there is no difference or no relationship between the variables being studied. In this case, the null hypothesis would suggest that there is no difference between men and women in their opinions about marriage.

Question 3

The null hypothesis is rejected whenever:

Accepted Answer

The null hypothesis is rejected when there is a low probability that the obtained results could be due to random error. This is usually determined by looking at the p-value, which is a measure of the strength of evidence against the null hypothesis. If the p-value is less than the chosen level of significance (usually 0.05), then the null hypothesis is rejected in favor of the alternative hypothesis. Past studies, researcher conviction, or lack of effect of the independent variable are not sufficient reasons to reject the null hypothesis.

Question 4

A researcher employs inferential statistics to examine the difference in mean scores obtained by fourth grade boys and girls in a standardized math test. In this case, inferential statistics:

Accepted Answer

Inferential statistics allow researchers to make inferences about a population based on a sample. In this case, the researcher is using inferential statistics to test the hypothesis that there is a difference in mean scores between fourth grade boys and girls on a standardized math test. The researcher is interested in determining whether the difference between the means is statistically significant, meaning that it is unlikely to have occurred by chance.

Question 5

Inferential statistics _____.

Accepted Answer

Inferential statistics are used to make conclusions about a larger population based on a sample of data. They involve using probability and hypothesis testing to determine whether the sample data is likely to represent the population as a whole.

Question 6

If a researcher proposes that there is a difference in the hiring preferences between veterans and nonveterans, such a situation represents the _____ hypothesis. If the researcher proposes that there is no difference in the hiring preferences between veterans and non-veterans, such a situation represents the _____ hypothesis.

Accepted Answer

The researcher proposing a difference in hiring preferences between veterans and nonveterans represents a research hypothesis, while proposing no difference represents a null hypothesis. Therefore, option B is the best choice.

Question 7

According to the _____ hypothesis, the independent variable has no effect.

Accepted Answer

The null hypothesis states that there is no significant difference or relationship between variables. In other words, the independent variable has no effect on the dependent variable.

Question 8

The research hypothesis states that the:

Accepted Answer

The research hypothesis is a statement about the relationship between the independent and dependent variables. It is the prediction that the independent variable will have an effect on the dependent variable. Therefore, choice B is the correct answer.

Question 9

A researcher studying the gender-based differences in the use of disciplinary practices predicted that men use power-oriented practices more frequently than women. In this case, the research hypothesis would suggest that:

Accepted Answer

The research hypothesis predicts that men use power-oriented practices more frequently than women. Therefore, the answer is B - men use power-oriented practices more than women.

Question 10

A _____ result is one that has a very low probability of occurring if the population means are equal.

Accepted Answer

A significant result is statistically unlikely to have occurred by chance if the null hypothesis (which assumes that the population means are equal) is true. This indicates that there is likely a true difference between the groups being compared.

Question 11

When testing the differences between means, the _____ hypothesis suggests that population means are not equal.

Accepted Answer

The research hypothesis is the one being tested in a statistical analysis, and in the case of testing differences between means, the research hypothesis suggests that the population means are not equal. The null hypothesis, on the other hand, assumes that there is no difference between the population means. The practical hypothesis is not a commonly used statistical term, and the significant hypothesis is not a correct term for describing the hypothesis being tested in this scenario.

Question 12

Aden finds that, on an average, men have higher starting salaries than women. In order to conclude that the differences in starting salaries are true differences and not a result of random error, Aden would employ the use of _____ statistics.

Accepted Answer

Aden would employ inferential statistics to determine if the differences in starting salaries are statistically significant and not just due to chance. This involves analyzing the data and making inferences about the population based on sample data.

Question 13

Arafa has collected data on the relationship between physical attractiveness and judgments of personality characteristics. In order to determine if the results obtained from the sample are representative of the population, Arafa will need to employ _____ statistics.

Accepted Answer

In order to determine if the results obtained from the sample are representative of the population, Arafa will need to employ inferential statistics. Inferential statistics allows researchers to make generalizations about a population based on a sample. Descriptive statistics summarize the data obtained within a specific sample, but do not allow for generalizations to be made about the population as a whole. Qualitative and ordinal statistics are not appropriate for this type of analysis.

Question 14

The null hypothesis:

Accepted Answer

The null hypothesis is a precise statement that assumes no effect or no difference, which makes it useful for statistical testing.

Question 15

When testing the differences between means, the null hypothesis suggests that any observed difference is due to _____.

Accepted Answer

The null hypothesis assumes that any observed difference between means is due to random error, meaning it is not due to any systematic effect or manipulation.

Question 16

Adrian found no significant difference in the amount of money spent on entertainment on those students who live on campus versus those who live off campus. Based on this finding, Adrian would:

Accepted Answer

Since there was no significant difference found, this means that the null hypothesis (which states that there is no difference) cannot be rejected. Therefore, Adrian would accept the null hypothesis.

Question 17

When comparing the differences in the ratings of responsibility for an automobile accident between male and female drivers, the null hypothesis would suggest that:

Accepted Answer

The null hypothesis is typically formulated as the absence of a relationship or difference between two variables. In this case, the null hypothesis would suggest that there is no difference in the ratings of responsibility between male and female drivers, and any observed difference could be due to chance.

Question 18

According to her statistical analysis, an investigator found that significantly more men than women used punishment to discipline their children. Thus, the investigator would:

Accepted Answer

If the statistical analysis has found a significant difference between men and women in their use of punishment to discipline their children, then it would be appropriate to reject the null hypothesis, which assumes that there is no difference. Accepting the null hypothesis (A) would be incorrect in this case. Making a Type II error (C) would occur if the investigator failed to reject the null hypothesis when there actually is a difference between men and women in their use of punishment. Making a Type I error (D) would occur if the investigator incorrectly rejected the null hypothesis when there is actually no difference.

Question 19

Which of the following is used to determine whether the results held up if an experiment was conducted repeatedly, each time with a new sample?

Accepted Answer

Inferential statistics are used to determine the likelihood that the results obtained from a sample are due to chance or if they represent a true difference or relationship in the population. This allows researchers to make conclusions about the population based on the sample and to determine if the results are reliable if the experiment were repeated with a new sample. Descriptive statistics describe the characteristics of the sample, but do not provide information about the generalizability of the results. The research hypothesis is the hypothesis that the researcher is testing, while the null hypothesis is the hypothesis that there is no significant difference or relationship in the population. While the null hypothesis is important in hypothesis testing, it does not directly address the issue of whether the results would hold up if the experiment were repeated with a new sample.

Question 20

A researcher assesses the length of the prison sentence for physically attractive and physically unattractive defendants. He believes that attractive defendants will receive shorter prison sentences than unattractive defendants. The null hypothesis would suggest that:

Accepted Answer

The null hypothesis states that there is no difference between the length of prison sentences for attractive and unattractive defendants. This is the baseline assumption that needs to be either rejected or failed to be rejected through statistical analysis. Option B and C are incorrect because they assume a specific direction of difference in sentence length, which do not conform to the null hypothesis. Option D is incorrect because it presents an entirely different variable as a possible explanation for the observed difference, which is not part of the research hypothesis.

Quiz 13: Understanding Research Results: Statistical Inference