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Statistics- homework one
Annie wants to estimate the percentage of homeowners that own at least one dog. She surveys 75 randomly selected individuals to determine whether or not they own dogs. What is the population? - ANSWER-all homeowners The population is the entire group of individuals being studied. In this case, the population is all homeowners. Annie wants to estimate the average number of AP classes a student at her high school takes. She decides to randomly select 6 classes and use all the students in those 6 classes to estimate the average. What type of sampling did Annie use? - ANSWER-Cluster sampling Because Annie chose several classes at random and then took all the students from those classes, she used cluster sampling. Note that cluster sampling could be misrepresentative in this case because she might select one or more AP classes in her sample. systematic sampling - ANSWER-An example of systematic sampling would be going to the student directory, starting at a random student, and then polling every 10th student in the directory. This is not systematic sampling because the classes she chose were picked at random, not based on a list of students. Raymond wants to estimate the percentage of parents that use cloth diapers. He asks a randomly selected group of 200 parents whether or not they use cloth diapers. What is the data? - ANSWER-specific "yes" or "no" responses to the survey
Data is a set of observations. In this case, the data is specific "yes" or "no" responses to the survey. Anna wants to estimate the mean number of siblings for each student in her school. She records the number of siblings for each of 75 randomly selected students in the school. What is the statistic? - ANSWER-the mean number of siblings for the randomly selected students A statistic is a numerical characteristic of the sample. In this case, the statistic is the mean number of siblings for the randomly selected students. Angela is studying the mean blood pressure of all students attending her college. She collects data from the 38 students in her statistics class. Which type of sampling is used? - ANSWER-Convenience sampling This scenario demonstrates convenience sampling. Convenience sampling involves selecting individuals from the population that are easily accessible, or from which data is easily obtained. Angela wants to estimate the mean number of siblings for each student in her school. She records the number of siblings for each of 200 randomly selected students in the school. What is the data? - ANSWER-the specific number of siblings for each randomly selected student Data is a set of observations. In this case, the data is the specific number of siblings for each randomly selected student. When considering different sampling methods, STRATIFIED sampling includes the steps: _______. - ANSWER-divide the population into groups; use simple random sampling to identify a proportionate number of individuals from each group
To study the mean respiratory rate of all people in his state, Frank samples the population by dividing the residents by towns and randomly selecting 12 of the towns. He then collects data from all the residents in the selected towns. Which type of sampling is used? - ANSWER-Cluster sampling This scenario demonstrates cluster sampling. Cluster sampling involves dividing the population into groups and randomly selecting several of these groups. True or False? In reference to different sampling methods, cluster sampling includes the steps: use simple random sampling to select a set of groups; every individual in the chosen groups is included in the sample. - ANSWER-True It is true that cluster sampling includes the steps: use simple random sampling to select a set of groups; every individual in the chosen groups is included in the sample. In reference to different sampling methods, is the following statement true or false? Systematic sampling includes the steps: identify individuals of the population that are easily accessible; obtain data from these individuals. - ANSWER-False Systematic sampling includes the steps: list the members of the population; use simple random sampling to select a starting point in the population; let k = (number of individuals in the population)/(number of individuals needed in the sample); choose every kth individual in the list starting with the one that was randomly selected. Convenience sampling includes the steps: identify individuals of the population that are easily accessible; obtain data from these individuals.
Sharon wants to estimate the percentage of parents that use cloth diapers. She asks a randomly selected group of 75 parents whether or not they use cloth diapers. What is the population? - ANSWER-all parents The population is the entire group of individuals being studied. In this case, the population is all parents. Your answer: Is the statement below true or false? A parameter is a number that is used to represent a population characteristic and that generally cannot be determined easily. - ANSWER-True It is true that a parameter is defined as a number that is used to represent a population characteristic and that generally cannot be determined easily. You want to find the average test score of the students in every math class in 11th grade. There are 15 math classes in 11th grade. You survey the scores of 7 math classes, and you calculate that the average test score is 83%. Which of the following represent the sample and the parameter in this scenario? - ANSWER-Sample: 7 math classes Parameter: There is no parameter in this scenario. There are 6000 people who attended a political debate at a convention center. There are three candidates who are participating in the debate - Mr. Smith, Mr. Jones, or Ms. Roberts. You want to find out which candidate is most popular amongst the people attending. You ask 500 people as they walk into the convention center. Which represents the population in this scenario? - ANSWER-The 6000 people attending the debate Is the statement below true or false?
A parameter is a number that is used to represent a population characteristic. In this case, the parameter is the percentage of all homeowners that own at least one dog. Douglas wants to estimate the percentage of homeowners that own at least one dog. He surveys 125 randomly selected homeowners to determine whether or not they own dogs. What is the statistic? - ANSWER-the percentage of surveyed homeowners that own at least one dog A statistic is a numerical characteristic of the sample. In this case, the statistic is the percentage of surveyed homeowners that own at least one dog. A 2016 Pew Research poll estimated the proportion of people supporting each presidential candidate in the fall election. They based their estimates on telephone interviews of 2,010 adults living in all 50 U.S. states. They asked each participant which presidential candidate they support, and used that data to calculate the proportions. What is the statistic in this experiment? - ANSWER-The proportions of participants who support each presidential candidate. Remember that the statistic in an experiment is the numerical characteristic of the sample. Therefore, the statistic in this example is the proportions in the sample, the proportions of participants who support each candidate. In order to study the wrist sizes of people in her town, Kathryn samples the population by dividing the residents by age and randomly selecting a proportionate number of residents from each age group. Which type of sampling is used? - ANSWER-Stratified sampling This scenario demonstrates stratified sampling. Stratified sampling involves dividing the population into groups and randomly selecting a proportionate number of individuals from each group.
Is the statement below true or false? A sample is all individuals, objects, or measurements whose properties are being studied. - ANSWER-False A population is defined as all individuals, objects, or measurements whose properties are being studied. A sample is defined as a subset of the population studied. In order to study the shoe sizes of people in his town, Billy samples the population by dividing the residents by age and randomly selecting a proportionate number of residents from each age group. Which type of sampling is used? - ANSWER-Stratified sampling This scenario demonstrates stratified sampling. Stratified sampling involves dividing the population into groups and randomly selecting a proportionate number of individuals from each group. Is the statement below true or false? Data is a subset of the population studied. - ANSWER-False A sample is defined as a subset of the population studied. Data is defined as a set of observations or possible outcomes. In order to study the mean pulse rate of people in his town, Jerry samples the population by dividing the residents by regions and randomly selecting 12 of the regions. He collects data from all residents in the selected regions. Which type of sampling is used? - ANSWER-Cluster sampling
This scenario demonstrates convenience sampling. Convenience sampling involves selecting individuals from the population that are easily accessible, or from which data is easily obtained. What is all individuals, objects, or measurements whose properties are being studied?
- ANSWER-population A population is defined as all individuals, objects, or measurements whose properties are being studied. William is studying the hair colors of all students attending his college. He collects data from the 25 students in his statistics class. Which type of sampling is used? - ANSWER-Convenience sampling This scenario demonstrates convenience sampling. Convenience sampling involves selecting individuals from the population that are easily accessible, or from which data is easily obtained. Joseph wants to estimate the mean number of siblings for each student in his school. He records the number of siblings for each of 200 randomly selected students in the school. What is the sample? - ANSWER-the 200 randomly selected students A sample is a specific subset of the entire group of individuals being studied. In this case, the sample is the 200 randomly selected students. Tina is studying the shoe sizes of all students attending her university. She samples the student population by selecting every 18th student from an alphabetical list of the students.
Which type of sampling is used? - ANSWER-Systematic sampling This scenario demonstrates systematic sampling. Systematic sampling involves selecting every nth individual from the list of individuals in the population based on a randomly selected starting position. Ruby is studying the mean waist size of all students attending her college. She collects data from the 25 students in her statistics class. Which type of sampling is used? - ANSWER-Convenience sampling This scenario demonstrates convenience sampling. Convenience sampling involves selecting individuals from the population that are easily accessible, or from which data is easily obtained. When considering different sampling methods, systematic sampling includes the steps: _______. - ANSWER-list the members of the population; use simple random sampling to select a starting point in the population; let k = (number of individuals in the population)/(number of individuals needed in the sample); choose every kth individual in the list starting with the one that was randomly selected. To study the mean head size of all athletes in his school, Kenneth obtains a list of the athletes and collects data from every 6th person on the list. Which type of sampling is used? - ANSWER-Systematic sampling This scenario demonstrates systematic sampling. Systematic sampling involves selecting every nth individual from the list of individuals in the population based on a randomly selected starting position.
