1. A survey of 1353 American households found that 18% of the households own a computer. What is the sample?

1. 1353 American households

2. 18% of households

3. all American households

4. all computer users

2. A survey of 2625 elementary school children found that 28% of the children could be classified as obese. What is the population?

1. 2625 elementary school children

2. 28% of children

3. all elementary school children

4. all children

3. A recent survey by the alumni of a major university indicated that the average salary of 10,000 of its 300,000 graduates was $125,000 which was lower than the average salary of $126, 357 for all alumni. Which numerical value is a statistic?

1. 10,000

2. $125,000

3. $126, 357

4. 300,000

4. The average salary of all 54,631 assembly-line employees at a certain car manufacturer is $33,000. A sample of 15,000 employees was taken, and their average salary was $34,455. Which numerical value is a parameter?

1. 15,000

2. $33,000

3. $34,455

4. 54,631

5. In a very large school, 35 sophomores, 35 juniors, and 49 seniors are randomly selected.Which sampling technique was used?

1. simple random

2. convenience

3. systematic

4. stratified

6. A study where a drug was given to 57 patients and a placebo to another group of 57 patients to determine if the drug has an effect on a patient's illness.Which method of data collection was used?

1. observational study

2. survey

3. experiment

4. simulation

7. At a local community college, five statistics classes are randomly selected out of 20 and all the students from each class are interviewed.Which sampling method was used?

1. simple random

2. stratified

3. cluster

4. convenience

8. Every fifth person boarding a plane is searched thoroughly.Which sampling method was used?

1. cluster

2. convenience

3. systematic

4. stratified

9. A community college student interviews everyone in his statistics class to determine the percentage of students that own a car.Which sampling method was used?

1. simple random

2. systematic

3. cluster

4. convenience

10. A lobbyist for a major airspace firm assigns a number to each legislator and then uses a computer to randomly generate ten numbers.The lobbyist contacts the legislators corresponding to these numbers.What sampling method was used?

1. simple random

2. stratified

3. systematic

4. cluster

11. A new headache medicine was given to a group of 25 subjects who had headaches and a fake pill was given to a different group of 25 subjects.Four hours after taking the new remedy, 20 of the subjects who were given the fake pill reported that their headaches had disappeared.From this information you may conclude:

1. that the remedy is effective for the treatment of headaches.

2. that the new treatment is better than aspirin.

3. nothing, because there was a strong placebo effect

4. nothing, because the sample size is too small.

12. A nutritionist wants to study the effect of storage time (6, 12, and 18 months) on the amount of vitamin C present in dried fruit when stored for these lengths of time.Six fruit packs were randomly assigned to each of the three storage times.The treatment, experimental unit and response are respectively:

1. A specific storage time, amount of vitamin C, a fruit pack

2. A fruit pack, amount of vitamin C, a specific storage time

3. A specific storage time, a fruit pack, amount of vitamin C

4. Random assignment, a fruit pack, amount of vitamin C

13. A study gathered data and found that the results were strongly skewed left. Which measure of center, the mean or the median, best represents the data?

1. The mean because it is the average.

2. The mean because it is the most representative measure when there is skew.

3. The median because it is the most representative measure when there is skew.

4. Without seeing the data there is not enough information to say one way or the other.

14. What is called when experimental results are unreliable because the experimenter cannot tell what factor actually had an effect on the variable?

1. confounding

2. cause and effect

3. convenience

4. blinding

15. A local newspaper ran a survey by asking, "Because the Mayor has donated money to many charities, do you support her re-election for the next term?"

This question has bias. Explain how this bias might affect the results of this survey.

Re-write the question to remove the bias.

16. Nike developed a new type of walking shoe designed to help delay the onset of arthritis in the knee.Eighty people with early signs of arthritis were randomly selected for the study.Half of the subjects wore the Nike shoe, and the other half wore one that looked exactly like the experimental sneaker.The individuals wore the sneakers every day.At the end of the study, their symptoms were evaluated, and an MRI was performed on their knees.

A.Identify the subjects, the explanatory, and response variables.

Subjects -

Explanatory variable (treatment) -

Response variable -

B)The experiment was described as a double-blind study.Explain what this mean.