Question

.Which of the following best describes a sample survey?
(7 Points)

Choose the option that correctly defines a sample survey in the context of statistical study designs.

A study that collects data from a subset of a population to estimate population parameters.

A study where researchers manipulate variables to observe effects.

A study that observes subjects without intervention or manipulation.

A study that uses only census data.
2.What is the main purpose of random assignment in an experiment?
(7 Points)

Select the best explanation for why subjects are randomly assigned to treatment groups.

To ensure every subject receives every treatment.

To reduce bias and create comparable groups.

To increase the sample size.

To guarantee the experiment is double-blind.
3.Which type of bias occurs when certain groups are less likely to respond to a survey?
(7 Points)

Identify the bias that results from a lack of responses from some groups.

Sampling bias

Response bias

Nonresponse bias

Measurement bias
4.Why is random sampling important in a sample survey?
(7 Points)

Choose the main reason random sampling is used when selecting a sample.

It helps ensure the sample is representative of the population.

It guarantees no bias will occur.

It increases the sample size.

It makes data collection faster.
5.A researcher observes students in a cafeteria without interfering. What type of study is this?
(7 Points)

Select the correct study design based on the description.

Sample survey

Experiment

Observational study

Census
6.Which statement about increasing sample size is true?
(7 Points)

Choose the correct effect of increasing the sample size in a study.

It increases the expected variability of the sample statistic.

It decreases the expected variability of the sample statistic.

It has no effect on variability.

It always eliminates bias.
7.What does the margin of error describe in a sampling distribution?
(7 Points)

Select the best definition of margin of error.

The average value of the sample statistic.

The range within which the population parameter is likely to fall.

The total number of samples taken.

The difference between two sample statistics.
8.A study finds that 60% of a random sample of 200 students prefer online learning. What is the parameter?
(7 Points)

Identify the population parameter in this context.

60%

200 students

The proportion of all students who prefer online learning

The average age of the students
9.Which of the following is an example of response bias?
(7 Points)

Choose the scenario that best illustrates response bias.

Surveying only students in honors classes.

Respondents give answers they think are socially acceptable.

Not enough people respond to a survey.

Selecting every 10th person from a list.
10.Why can't results from a non-random sample be generalized to the population?
(7 Points)

Select the main reason non-random samples limit generalizability.

They may not be representative of the population.

They always have a larger margin of error.

They require more complex analysis.

They are always biased.
11.What is the main difference between an experiment and an observational study?
(7 Points)

Choose the statement that best distinguishes these two study designs.

Experiments involve manipulation of variables; observational studies do not.

Observational studies use random assignment.

Experiments never use random sampling.

Observational studies always have larger samples.
12.If a sample is randomly selected, what does this allow us to do?
(7 Points)

Select the best inference that can be made from a randomly selected sample.

Make inferences about the population.

Guarantee no bias exists.

Ensure all subgroups are equally represented.

Eliminate the need for a large sample size.
13.Which scenario best illustrates sampling bias?
(7 Points)

Choose the example that demonstrates sampling bias.

Surveying only morning students about school lunch preferences.

Randomly selecting students from all grades.

Asking students to fill out an anonymous survey.

Using a large sample size.
14.What does a sampling distribution show?
(7 Points)

Select the best description of a sampling distribution.

The distribution of the population parameter.

The distribution of a sample statistic from repeated samples.

The distribution of survey questions.

The distribution of experimental treatments.
15.Why is it important to consider the scope and validity of statistical inferences?
(7 Points)

Choose the best reason for evaluating the scope and validity of inferences.

To ensure conclusions accurately reflect the population studied.

To increase the sample size.

To reduce the number of variables.

To guarantee the study is an experiment.

Answer 1

1. A study that collects data from a subset of a population to estimate population parameters.

2. To reduce bias and create comparable groups.

3. Nonresponse bias.

4. It helps ensure the sample is representative of the population.

5. Observational study.

6. It decreases the expected variability of the sample statistic.

7. The range within which the population parameter is likely to fall.

8. The proportion of all students who prefer online learning.

9. Respondents give answers they think are socially acceptable.

10. They may not be representative of the population.

11. Experiments involve manipulation of variables; observational studies do not.

12. Make inferences about the population.

13. Surveying only morning students about school lunch preferences.

14. The distribution of a sample statistic from repeated samples.

15. To ensure conclusions accurately reflect the population studied.