I am respectfully requesting help with the following assignment. I am struggling in this chapter of statistics...
Define the term sample?
A) A sample is a numeric characteristic of a sample
B) A sample is a numeric characteristic of a population
C) A sample is the entire collection of individuals about whom we would like to obtain information
D) A sample is a subset of the entire collection of individuals about whom we like to obtain information ( i chose this one)
2. Which of the following are reasons to use sampling?
I. Sampling saves time.
II. Sampling saves money.
III. Sampling is sometimes more precise than analyzing the whole population through a census.
A) I and II
B) I and III
C) II and III
D) All of above ( I chose this one)
3. Which is true about sampling?
I. An attempt to take a census will always result in less bias than using a sample.
II. Sampling error is usually reduced when the sample size is larger.
III. Sampling error is the result of random variations and is always present
A) all of above
B) I only
C) II and III
D) II only ( I chose this one)
E) III only
4. The Stanford-Binet IQ test is known to have a mean of 100 and a standard deviation of 15. A sample of 25 students was given the exam, and the mean for this group was 110.
Select the term which best describes the number 100.
A) population
B) sample
C) statistic ( i chose this one)
D) parameter
5)Mr. Smith works at a computer consultant company that provides technical information to computer departments of various manufacturing companies. Mr. Smith is alarmed at the number of spyware programs on the internet. He locates a study that states that 75% of all computers have been infected with a virus at some time in the past year. Mr. Smith wants to determine if his clients have experienced viruses on their computers at a comparable rate. He contacts a random sample of his clients and he finds that only 30% of his clients reported a computer infected with a virus.
What term best describes the figure of 30%?
A) Statistic
B) Parameter (i chose this one)
C) bias
D) sample
E) population
6)A local school district decides to randomly test high school students for attention deficit disorder (ADD). There are three high schools in the district, each with grades 9-12. There are a total of 1500 students in the three high schools. The school board pools all of the students together and randomly samples 250 students.
The percentage of high school students in the school district with ADD is known as:
A) census
B) the sampling method
C) the sample
D) the population parameter of interest ( i chose this one)
E) the sampling frame
7)The total number of students from question 6 represents what?
A) Voluntary sampling
B) the population (I chose this one)
C) the population parameter of interest
D) a census
E) the sample
8) A magazine publisher will mail a survey to 12% of its subscribers that will be chosen at random. The survey asks about the quality of its subscription service.
A listing of all of the subscribers, who have an equal and random chance to be chosen for this survey, represent what?
A) Census
B) the sampling method
C) the sampling frame ( i chose this one)
D) the sample
E) the population parameter of interest
9) Before premiering a blockbuster movie at a theater, test screenings are done beforehand. A small number of selected theaters are chosen geographically throughout the country. Each theater chosen is supposed to be representative of theatergoers throughout the country. Everyone is interviewed when the movie is over.
Identify the type of sampling used in this example
A) voluntary response
B) stratified
C) multistage
D) cluster ( I chose this one)
E) attempted census
10) A newly-premiered play just ended that evening at a local theater. Theater management briefly interviews every seventh person leaving the theater to see if that person will recommend the play at that theater to other people.
Identify the type of sampling used in this example
A) Cluster
B) voluntary response
C) convienience
D) systematic ( i chose this one)
E) stratified
11) A magazine publisher mails a survey to every subscriber asking about the quality of its subscription service.
Mailing a survey to every subscriber represents what type of sampling?
A) random
B) stratified
C) attempted census ( I chose this one)
D) cluster
E) systematic
12) A newspaper reporter randomly sampled households by telephone during various times of the day. The people sampled are within the area of the newspaper's distribution. The newspaper reporter asked, "Are you patriotic in a time of war or armed conflict?"
What, if any, will be the most noticeable bias for this survey?
A) Undercoverage of the population
B) Nonresponse bias ( i chose this one)
C) Voluntary response bias
D) Response bias
E) There does not seem to be any bias.
13) A referendum has been put forward in Christian County to enact a weekday curfew for teenagers. Radio station WTIM, a station that plays easy-listening music, is conducting a survey to determine what proportion of Christian County citizens support the referendum. Throughout the day the radio station airs announcements asking listeners to call in their opinion on the following question: "Should Christian County enact a weekday curfew for teenagers?" The goal of the survey is to identify if residents of Christian County feel support this proposal. Of course, people who are selected for the survey can elect to participate or not participate.
Identify how this survey design has undercoverage bias
A) Some listeners may refuse to participate, and those who refuse may differ on some characteristics from those who choose to respond. ( I chose this one)
B) The only people who can participate in the survey are the listeners of the station; non-listeners are excluded. The listeners may not be representative of the population of citizens of Christian County.
C) Some listeners will participate and some will not. Those who do participate tend to be those people who feel strongly about the issue.
1. correct
2. Wrong. Look up definitions of 'sample" and "Census".
3. Wrong. Look up sampling error.
4. Wrong. Look up statistic and parameter.
5. Wrong. Look up statistic and parameter.
6. Right.
7. Right.
8. Right.
9. Right.
10. Right.
11. Right.
12. Wrong. What if you were asked this question? What would you say?
13. Wrong.
1 a
2a
3a
4a
5a
6a
7a
8a
9a
10a
Let's go through the answers step-by-step:
1) The correct answer is D) A sample is a subset of the entire collection of individuals about whom we like to obtain information.
2) The correct answer is D) All of the above. Sampling saves time, saves money, and is sometimes more precise than analyzing the whole population through a census.
3) The correct answer is C) II and III. Sampling error is usually reduced when the sample size is larger, and sampling error is the result of random variations and is always present.
4) The term "100" in this context is a statistic. It represents the mean for the sample of 25 students, not the entire population.
5) The term "30%" in this context is a statistic. It represents the percentage of Mr. Smith's clients who reported a computer infected with a virus, not the entire population.
6) The percentage of high school students in the school district with ADD is known as the population parameter of interest.
7) The total number of students from question 6 represents the population.
8) A listing of all the subscribers, who have an equal and random chance to be chosen for the survey, represents the sampling frame.
9) The type of sampling used in this example is cluster sampling. The selected theaters are considered clusters.
10) The type of sampling used in this example is systematic sampling because every seventh person leaving the theater is interviewed.
11) Mailing a survey to every subscriber represents attempted census since the survey is sent to the entire population.
12) The most noticeable bias for this survey is nonresponse bias. People who choose not to participate may have different opinions on patriotism in a time of war or armed conflict.
13) This survey design has undercoverage bias because the only people who can participate are the listeners of the radio station. Non-listeners are excluded, which may result in a sample that is not representative of the population of citizens of Christian County.
I hope this helps clarify the answers for you! Let me know if you have any more questions.
Sure, I can help you with your statistics assignment. Let's go through each question one by one and discuss the correct answers with explanations:
1. Define the term sample?
D) A sample is a subset of the entire collection of individuals about whom we like to obtain information.
Explanation: A sample is a selected subset of a population, which represents the larger group. It is a smaller and more manageable group that is used to gather information and make inferences about the population as a whole.
2. Which of the following are reasons to use sampling?
D) All of the above (I and II, and III).
Explanation: Sampling saves time and money compared to conducting a census, which involves collecting data from the entire population. It is also often more precise to use sampling when analyzing the whole population through a census is impractical.
3. Which is true about sampling?
C) II and III.
Explanation: Attempting to take a census may not always result in less bias than using a sample (Statement I is false). Sampling error tends to decrease as the sample size increases (Statement II is true). Sampling error is the result of random variations and is always present (Statement III is true).
4. The Stanford-Binet IQ test is known to have a mean of 100 and a standard deviation of 15. A sample of 25 students was given the exam, and the mean for this group was 110.
C) Statistic.
Explanation: In this case, the number 100 is the mean of the population, not the sample or parameter. A statistic is a value calculated from a sample, while a parameter is a value calculated from a population.
5. What term best describes the figure of 30%?
A) Statistic.
Explanation: In this scenario, the figure of 30% is a calculated value based on a sample of Mr. Smith's clients. It represents a characteristic of the sample, hence it is a statistics.
6. The percentage of high school students in the school district with ADD is known as:
D) The population parameter of interest.
Explanation: In this context, the percentage of high school students in the school district with ADD is the population parameter of interest since it represents a characteristic of the entire population.
7. The total number of students from question 6 represents what?
B) The population.
Explanation: The total number of students in the three high schools in the district represents the entire population of students in question 6.
8. A listing of all the subscribers, who have an equal and random chance to be chosen for this survey represents what?
C) The sampling frame.
Explanation: The sampling frame is the list of all the individuals or units in the population from which a sample is selected. In this case, the subscribers who have an equal and random chance to be chosen for the survey form the sampling frame.
9. Identify the type of sampling used in this example.
D) Cluster.
Explanation: In cluster sampling, the population is divided into clusters or groups, and a random sample of the clusters is selected. In this case, the chosen theaters geographically throughout the country represent the clusters, and each theater is supposed to be representative of theatergoers throughout the country.
10. Identify the type of sampling used in this example.
D) Systematic.
Explanation: Systematic sampling involves selecting every nth individual from the population. In this case, every seventh person leaving the theater is being interviewed, which is an example of systematic sampling.
11. Mailing a survey to every subscriber represents what type of sampling?
C) Attempted census.
Explanation: Mailing a survey to every subscriber is an attempt to collect data from the entire population, which is an attempted census.
12. What, if any, will be the most noticeable bias for this survey?
B) Nonresponse bias.
Explanation: Nonresponse bias occurs when those who choose to respond to a survey have different characteristics than those who do not respond. In this survey, some people may refuse to participate, leading to potential nonresponse bias.
13. Identify how this survey design has undercoverage bias.
A) Some listeners may refuse to participate, and those who refuse may differ on some characteristics from those who choose to respond.
Explanation: Undercoverage bias occurs when certain groups within the population are excluded or have a lower chance of being selected for the survey. In this survey, only listeners of the station can participate, and those who refuse to participate may have different characteristics from those who choose to respond, leading to potential undercoverage bias.
I hope this explanation helps you understand the concepts better. Let me know if you have any further questions!