Statistics Homework 1 MyLab Stats
Determine whether the value given below is from a discrete or continuous data set. The volume of cola in a can is 11.5 oz. nothing
A continuous data set because there are infinitely many possible values and those values cannot be counted.
Determine whether the given value is from a discrete or continuous data set. When a car is randomly selected, it is found to have 8 windows.
A discrete data set because there are a finite number of possible values.
Which of the following would NOT cast doubt of the usefulness of sample data?
An effective sampling method
Identify which type of sampling is used: random, systematic, convenience, stratified, or cluster. To determine customer opinion of their pricing, Greyhound Lines randomly selects 110 busses during a certain week and surveys all passengers on the busses. Which type of sampling is used?
Cluster
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?
Cluster
Identify which type of sampling is used: random, systematic, convenience, stratified, or cluster. A newspaper asks its readers to call in their opinion regarding the number of books they have read this month. Which type of sampling is used?
Convenience
Identify the type of observational study. A researcher plans to obtain data by interviewing siblings of victims who perished in a tsunami to see how they're coping now. nothing Choose the correct type of observational study below.
Cross-sectional
Which of the following is associated with a parameter?
Data that were obtained from an entire population.
Determine whether the value is from a discrete or continuous data set. Number of days of rainfall in a year is 15 Is the value from a discrete or continuous data set?
Discrete
Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 547 subjects, each was asked how often he or she drank milk. The survey subjects were internet users who responded to a question that was posted on a news website.
It is flawed because it is a voluntary response sample.It
Which of the following would be classified as categorical data?
Hair color
Explain the difference between a single-blind and a double-blind experiment.
In a single-blind experiment, the subject does not know which treatment is received. In a double-blind experiment, neither the subject nor the researcher in contact with the subject knows which treatment is received.
Determine whether the sampling method described below appears to be sound or is flawed. In a survey of 534 human resource professionals, each was asked about the importance of the appearance of a job applicant. The survey subjects were randomly selected by pollsters from a reputable market research firm.
It appears to be sound because the data are not biased in any way.
Which of the following consists of discrete data?
Number of suitcases on a plane
A study is conducted to measure children's growth rates without any treatment applied to the children. What best classifies this study?
Observational Study
Determine whether the description corresponds to an observational study or an experiment. Research is conducted to determine if there is a relation between Parkinson's disease and childhood head trauma. Does the description correspond to an observational study or an experiment?
Observational Study
A study of an association between which ear is used for cell phone calls and whether the subject is left-handed or right-handed began with a survey e-mailed to 5000 people belonging to an otology online group, and 717 surveys were returned. (Otology relates to the ear and hearing.) What percentage of the 5000 surveys were returned? Does that response rate appear to be low? In general, what is a problem with a very low response rate?
Of the 5000 surveys, [ 14% ] were returned. This response rate [ appears ] to be low. (Round to the nearest whole number as needed.) What is a problem with a very low response rate? It creates a serious potential for getting a biased sample that consists of those with a special interest in the topic.
Determine whether the given value is a statistic or a parameter. A sample of employees is selected and it is found that 65 % own a computer.
Statistic because the value is a numerical measurement describing a characteristic of a sample.
When testing a new treatment, what is the difference between statistical significance and practical significance? Can a treatment have statistical significance, but not practical significance?
Statistical significance is achieved when the result is very unlikely to occur by chance. Practical significance is related to whether common sense suggests that the treatment makes enough of a difference to justify its use. It is possible for a treatment to have statistical significance, but not practical significance.
A sample of seniors is selected and it is found that 40% own a television.
Statistics because the value is a numerical measurement describing a characteristic of a sample.
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?
Random
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 she was randomly selected from all the taxpayers. nothing nothing nothing nothing Which type of sampling did the tax department use?
Random Sampling
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, 1226 adults were called after their telephone numbers were randomly generated by a computer, and 86 % were able to correctly identify the secretary of state. Which type of sampling did the research center use?
Random Sampling
Identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster. To determine her body temperature, Keri divides up her day into three parts: morning, afternoon, and evening. She then measures her body temperature at 3 randomly selected times during each part of the day. What type of sampling is used?
Stratified
Which sampling method subdivides the population into categories sharing similar characteristics and then selects a sample from each subdivision?
Stratified
Identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster. A market researcher has partitioned all residents of a certain region into categories of young left parenthesis age 0 dash 30 right parenthesis comma middle aged left parenthesis age 31 dash 60 right parenthesis comma and senior left parenthesis over age 60 right parenthesis . She is surveying 53 people from each category. What type of sampling is used?
Stratified Sampling
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 General Electric selects every 16th refrigerator that comes off the assembly line starting with the second until she obtains a sample of 110 refrigerators. Which type of sampling is used?
Systematic
Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. A researcher selects every 928th social security number and surveys the corresponding person. nothing nothing nothing Which type of sampling did the researcher use?
Systematic Sampling
Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. A woman is selected by a marketing company to participate in a paid focus group. The company says that the woman was selected because every 5000 th person in the phone number listings was being selected.
Systematic Sampling
State whether the data described below are discrete or continuous, and explain why. The numbers of hotels in cities
The data are Th discrete because the data can only take on specific values.
State whether the data described below are discrete or continuous, and explain why. The numbers of personal cars owned by different households nothing
The data are discrete because the data can only take on specific values.
State whether the data described below are discrete or continuous, and explain why. The numbers of police cars different cities have
The data are discrete because the data can only take on specific values.
State whether the data described below are discrete or continuous, and explain why. The numbers of programs installed on various computers
The data are discrete because the data can only take on specific values.
State whether the data described below are discrete or continuous, and explain why. The numbers of telephone lines in different regions
The data are discrete because the data can only take on specific values.
Determine whether the data described below are qualitative or quantitative and explain why. The times of birth of babies born at a certain hospital.
The data are quantitative because they consist of counts or measurements.
Determine whether the given description corresponds to an observational study or an experiment. In a study of 380 girls with a particular disease, the subjects were monitored with an EEG while asleep. Does the given description correspond to an observational study or an experiment?
The given description corresponds to an observational study.
Determine whether the given value is a statistic or a parameter. A homeowner measured the voltage supplied to his home on 5 days of a given week, and the average (mean) value is 137.2 volts.
The given value is a Th statistic for the week because the data collected represent a sample.
What does it mean for the findings of a statistical analysis of data to be statistically significant?
The likelihood of getting these results by chance is very small.Th
A particular country has 45 total states. If the areas of 20 states are added and the sum is divided by 20, the result is 215 comma 463 square kilometers. Determine whether this result is a statistic or a parameter.
The result is a statistic because it describes some characteristic of a sample.
Determine whether the given value is a statistic or a parameter. A study was conducted of all 969 workers in a certain state.
The value is a parameter because it is a numerical measurement describing some characteristic of a population.
A magazine, which does not accept free products or advertising from anyone, prints a review of new cars. Are there sources of bias in this situation?
There do not appear to be any sources of bias.
Determine whether the source given below has the potential to create a bias in a statistical study. A certain medical organization tends to oppose the use of meat and dairy products in our diets, and that organization has received hundreds of thousands of dollars in funding from an animal rights foundation.
There does appear to be a potential to create a bias. There is an incentive to produce results that are in line with the organization's creed and that of its funders.
Determine whether the study is an experiment or an observational study, and then identify a major problem with the study. In a survey, 1465 Internet users chose to respond to this question posted on a newspaper's electronic edition: "Is news online as satisfying as print and TV news?" 52% of the respondents said "yes."
This is an [observational study] because the researchers [do not attempt to modify] the individuals. What is a major problem with the study? This is a convenience sample with voluntary response, which has a high chance of leading to bias.
