Chapter 1 Homework

1.  Determine whether the underlined number is a statistic or a parameter.  A sample of professors is selected and it is found that 65% own a vehicle.

Choose the correct statement below.

1. Statistic because the value is a numerical measurement describing a characteristic of a sample.
2. Statistic because the value is a numerical measurement describing a characteristic of a population.
3. Parameter because the value is a numerical measurement describing a characteristic of a sample.
4. Parameter because the value is a numerical measurement describing a characteristic of a population.

2. Determine whether the given value is a statistic or a parameter.  A homeowner measured the voltage supplied to his home on all 365 days of a given year​, and the average​ (mean) value is 119.6 volts.

Choose the correct answer below.

1. The given value is a statistic for the year because the data collected represent a population.
2. The given value is a parameter for the year because the data collected represent a population.
3. The given value is a statistic for the year because the data collected represent a sample.
4. The given value is a parameter for the year because the data collected represent a sample.

3.  A particular country has 40 total states. If the areas of 25 states are added and the sum is divided by 25​, the result is 189,413 square kilometers. Determine whether this result is a statistic or a parameter.

Choose the correct answer below.

1. The result is a statistic because it describes some characteristic of a population.
2. The result is a parameter because it describes some characteristic of a sample.
3. The result is a statistic because it describes some characteristic of a sample.
4. The result is a parameter because it describes some characteristic of a population.

4. Which of the following is associated with a​ parameter?

Choose the correct answer below.

1. Data that were obtained from a voluntary poll at the end of a service call.
2. A numerical measurement describing some characteristic of a sample.
3. Data that were obtained from an entire population.
4. Data that were obtained from a sample.

5.  Determine whether the data described below are qualitative or quantitative and explain why.  The salaries of all state governors

Choose the correct answer below.

1. The data are quantitative because they don’t measure or count anything.
2. The data are qualitative because they don’t measure or count anything.
3. The data are qualitative because they consist of counts or measurements.
4. The data are quantitative because they consist of counts or measurements

6.  Which of the following would be classified as categorical​ data?

Choose the correct answer below.

1. Tree height
2. Number of suitcases on a plane
3. Amount of rainfall
4. Hair color

7.  In a​ double-blind experiment designed to test the effectiveness of a new medication as a treatment for lower back​ pain, 1643 patients were randomly assigned to one of three​ groups: (1) the 547 subjects in the placebo group were given pills containing no​ medication; (2) 550 subjects were in a group given pills with the new medication taken at regular​ intervals; (3) 546 subjects were in a group given pills with the new medication to be taken when needed for pain relief.

What does it mean to say that the experiment was​ “double-blind”?

Choose the correct answer below.

1. The subjects in the study did not know whether they were taking a placebo or the new​ medication, and those who administered the pills also did not know.
2. Both the subjects in the study and those who administered the pills knew whether they were taking a placebo or the new medication.
3. The subjects in the study did not know whether they were taking a placebo or the new​ medication, but those who administered the pills did know.
4. The subjects in the study were given the choice of taking the placebo or the new​ medication, but those who administered the pills did not know which group the subjects were in.

8.   Fill in the blank.

​__________ is used when subjects are assigned to different groups through a process of random selection.

9.  Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below.  A researcher selects every 941th social security number and surveys the corresponding person.

Which type of sampling did the researcher ​use?

1. Convenience sampling
2. Random sampling
3. Systematic sampling
4. Stratified sampling
5. Cluster sampling

10.  Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below.  In a poll conducted by a certain research​ center, 886 adults were called after their telephone numbers were randomly generated by a​ computer, and 29% were able to correctly identify the vice president.

Which type of sampling did the research center​ use?

1. Convenience sampling
2. Systematic sampling
3. Stratified sampling
4. Random sampling
5. Cluster sampling

11. Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below.

A man is selected by a marketing company to participate in a paid focus group. The company says that the man was selected because his name is among the first 500 in the phone number listings.  Which type of sampling did the marketing company​ use?

1. Random sampling
2. Convenience sampling
3. Systematic sampling
4. Cluster sampling
5. Stratified sampling

12.  Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster. To determine customer opinion of their safety features​, Daimler−Chrysler randomly selects 60 service centers during a certain week and surveys all customers visiting the service centers. 

Which type of sampling is​ used?

1. Cluster
2. Stratified
3. Systematic
4. Random
5. Convenience

13.  Identify which of these types of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster.  A large company wants to administer a satisfaction survey to its current customers. Using their customer​ database, the company randomly selects 30 customers and asks them about their level of satisfaction with the company. 

What type of sampling is​ used?

1. Stratified
2. Cluster
3. Convenience
4. Systematic
5. Random

14.  Identify which of these types of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster.

To determine her breathing rate​, Debra divides up her day into three​ parts: morning,​ afternoon, and evening. She then measures her breathing rate at 2 randomly selected times during each part of the day.

What type of sampling is​ used?

1. Systematic
2. Cluster
3. Random
4. Convenience
5. Stratified

15.  Identify the type of sampling​ used: random,​ systematic, convenience,​ stratified, or cluster.  To estimate the percentage of defects in a recent manufacturing​ batch, a quality control manager at Ford selects every 17th truck that comes off the assembly line starting with the second until she obtains a sample of 120 trucks.

Which type of sampling is​ used?

1. Systematic
2. Cluster
3. Stratified
4. Random
5. Convenience

16.  Identify the type of sampling used​ (random, systematic,​ convenience, stratified, or cluster​ sampling) in the situation described below.  A woman experienced a tax audit. The tax department claimed that the woman was audited because every 20,000th person on the taxpayer list was being audited.

Which type of sampling did the tax department​ use?

1. Random sampling
2. Stratified sampling
3. Systematic Sampling
4. Cluster sampling
5. Convenience sampling

17.  Identify which of these types of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster.  A market researcher has randomly selected three neighborhoods in a certain region. She is surveying all the people from each neighborhood.

What type of sampling is​ used?

1. cluster sampling
2. convenience sampling
3. stratified sampling
4. systematic sampling
5. random sampling

18.  Identify which type of sampling is​ used: random,​ systematic, convenience,​ stratified, or cluster.  An internet site asks its members to call in their opinion regarding their reluctance to provide credit information online. Which type of sampling is​ used?

1. Cluster
2. Stratified
3. Random
4. Convenience
5. Systematic

19.  Which sampling method divides the population up into​ sections, randomly selects some of those​ sections, then chooses all the members from the selected sections to​ study?

Choose the correct answer below.

1. Systematic
2. Stratified
3. Cluster
4. Convenience

20.  Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each​ subdivision?

Choose the correct answer below.

1. Systematic
2. Cluster
3. Convenience
4. Stratified

21. Which of the following corresponds to the case when every sample of size n has the same chance of being​ chosen? 

Choose the correct answer below.

1. Random sample
2. Experiment
3. Probability sample
4. Simple random sample

22.  Determine whether the description corresponds to an observational study or an experiment.  Research is conducted to determine if there is a relation between skin cancer and hair color.

Does the description correspond to an observational study or an​ experiment?

1. Experiment
2. Observational Study

23.  A study is conducted to measure​ children’s growth rates without any treatment applied to the children. What best classifies this​ study?

Choose the correct answer below.

1. Simple random sample
2. Discrete data
3. Experiment
4. Observational study