stats 1.1-1.3
The jersey numbers for players on a basketball team are listed below. Identify the level of measurement of the data set. Explain your reasoning.
Nominal. The data are categorized using numbers, but no mathematical computations can be made.
Determine whether the underlined number is a statistic or a parameter. In a study of all 4181 professors at a college, it is found that 35% own a vehicle.
Parameter because the value is a numerical measurement describing a characteristic of a population.
Determine whether the data set is a population or a sample. Explain your reasoning. The salary of each teacher in a school.
Population, because it is a collection of salaries for all teachers in the school.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. A population is the collection of some outcomes, responses, measurements, or counts that are of interest.
False. A population is the collection of all outcomes, responses, measurements, or counts that are of interest.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. A statistic is a measure that describes a population characteristic.
False. A statistic is a measure that describes a sample characteristic.
What is replication in an experiment? Why is replication important?
Replication is repetition of an experiment under the same or similar conditions. Replication is important because it enhances the validity of the results.
Determine whether the data set is a population or a sample. Explain your reasoning. The number of pets for 20 households in a town with 300 households
Sample, because the collection of the number of pets for 20 households is a subset of all households in the town
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Hair color A. The variable is qualitative because color describes an attribute or characteristic. B. The variable is quantitative because color describes an attribute or characteristic. C. The variable is qualitative because color is found by measuring or counting. D. The variable is quantitative because color is found by measuring
The variable is qualitative because color describes an attribute
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Breed of cat The variable is _____ because model numbers are _____.
The variable is qualitative because breed of cat are attributes or labels
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Employee ID numbers The variable is _____ because model numbers are _____.
The variable is qualitative because employee ID numbers are attributes or labels
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Model numbers The variable is _____ because model numbers are _____.
The variable is qualitative because model numbers are attributes or labels
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Parcel tracking numbers The variable is ____ because tracking numbers are _______
The variable is qualitative because tracking numbers are attributes or labels
what is a convenience sample
choose only members of the population that are easy to get - usually leads to bias
The two main branches of statistics are
descriptive statistics and inferential statistics.
what is a random sample
every member of the population has an equal chance of being selected
what is a descriptive statistic
involves organizing, summarizing, and displaying data (tables, charts, averages)
what is inferential statistics
involves using sample data to draw conclusions about a population
Name each level of measurement for which data can be qualitative.
nominal and ordinal
Name each level of measurement for which data can be quantitative.
ordinal, interval, ratio
A parameter is a numerical description of a
population characteristic
What is the difference between a census and a sampling?
A census includes the entire population. A sampling includes only part of the population.
How is a sample related to a population?
A sample is a subset of a population.
what is a stratified sample
Divide a population into groups (strata) and select a random sample from each group.
what is a cluster sample
Divide the population into groups (clusters) and select all of the members in one or more, but not all, of the clusters.
what is the nominal level of measurement
- qualitative data only - categorized using names, labels, or qualities - no mathematical computations can be made (preference)
what is the ordinal level of measurement
- qualitative or quantitative data - data can be arranged in order or ranked - differences between data entries is not meaningful (in order)
what is the Interval level of measurement
- quantitative data - data can be ordered - differences between data entries is meaningful - zero represents a position on a scale ( not an inherent zero - zero does not imply none) (temp.)
what is the ratio level of measurement
- similar to interval level - zero entry is an inherent zero (implies none) - a ratio of two data values can be formed - one data value can be expressed as a multiple of another
The top five books on the best seller list last year are shown below. Identify the level of measurement of the data set. Explain your reasoning.
. The data can be arranged in order, but the differences between data entries are not meaningful
The heights (in centimeters) of a sample of a species of plant 30 days after sprouting are shown below. Determine the level of measurement of the data set. Explain your reasoning.
.Ratio The data can be ordered and differences between data entries aremeaningful, and a zero entry is an inherent zero
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. The method for selecting a stratified sample is to order a population in some way and then select members of the population at regular intervals. A. False. The method for selecting a systematic sample is to order a population in some way and then select members of the population at regular intervals. B. False. The method for selecting a cluster sample is to order a population in some way and then select members of the population at regular intervals. C. True.
A. False. The method for selecting a systematic sample is to order a population in some way and then select members of the population at regular intervals.
In a poll, 1,003 men in a country were asked whether they favor or oppose the use of "federal tax dollars to fund medical research using stem cells obtained from human embryos." Among the respondents, 46% said that they were in favor. Identify the population and the sample. What is the population in the given problem? Choose the correct answer below. Identify the sample for the given problem. Choose the correct answer below.
All men in the country The 1,003 men selected
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. Using a systematic sample guarantees that members of each group within a population will be sampled. A. True. B. False. Using a stratified sample guarantees that members of each group within a population will be sampled. C. False. Using a cluster sample guarantees that members of each group within a population will be sampled.
B. False. Using a stratified sample guarantees that members of each group within a population will be sampled.
what is a systematic sample
Choose a starting value at random. Then choose every kth member of the population.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement. More types of calculations can be performed with data at the nominal level than with data at the interval level. A.True. B.False. The same types of calculations can be performed with data at the nominal level and with data at the interval level. C.False. More types of calculations can be performed with data at the interval level than with data at the nominal level.
False. More types of calculations can be performed with data at the interval level than with data at the nominal level.
What is the difference between an observational study and an experiment?
In an experiment, a treatment is applied to part of a population and responses are observed. In an observational study, a researcher measures characteristics of interest of a part of a population but does not change existing conditions.
Why is a sample used more often than a population?
It is usually impossible to count the entire population.
Determine whether the underlined number describes a population parameter or a sample statistic. Explain your reasoning. Sixty−seven of the 92 passengers aboard an airship survived an explosion.
The number is a population parameter because it is a numerical description of all of the passengers that survived.
Determine whether the underlined number describes a population parameter or a sample statistic. Explain your reasoning. A survey of 2216 adults in a country found that 74% think that militant terrorists are a major threat to the well-being of their country.
The number is a sample statistic because it describes the people in a sample, which is a subset of all of the people in the country.
In a recent study on the effects of sleep and test results, volunteers took a math test. The volunteers who had 8 hours of sleep were three times more likely to answer questions correctly on the math test than were sleep-deprived volunteers. Complete parts a through d. -Identify the sample used in the study. -What is the sample's population? -Which part of the study represents the descriptive branch of statistics? -Make an inference based on the results of the study.
The sample is the test results of the volunteers in the study. The population is the collection of the test results of all individuals who might ever complete the math test. The statement "three times more likely to answer questions correctly" is an example of descriptive statistics Individuals who are not sleep deprived will be more likely to answer math questions correctly than individuals who are sleep deprived.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. A placebo is an actual treatment.
The statement is false. A placebo is a fake treatment.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. A sample statistic will not change from sample to sample.
The statement is false. A sample statistic can change from sample to sample.
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. Data at the ratio level cannot be put in order. A. The statement is false. A true statement is "Data at the ratio level can be placed in a meaningful order." B. The statement is true. C. The statement is false. A true statement is "Data at the ratio level can be ordered, although it is impossible to determine if one data value is a multiple ofanother." D. The statement is false. A true statement is "Data at the ratio level can be ordered, although it is impossible to subtract data values."
The statement is false. A true statement is "Data at the ratio level can be placed in a meaningful order."
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. For data at the interval level, you cannot calculate meaningful differences between data entries. A. The statement is true. B. The statment is false. A true statement is "For data at the interval level, you cannot calculate meaningful differences between data entries." C. The statement is false. A true statement is "For data at the interval level, you can't order them, but you can calculate meaningful differences between dataentries." D. The statement is false. A true statement is "For data at the interval level, you can calculate meaningful differences between data entries."
The statement is false. A true statement is "For data at the interval level, you can calculate meaningful differences between data entries."
Determine whether the following statement is true or false. If it is false, rewrite it as a true statement. A double-blind experiment is used to increase the placebo effect.
The statement is false. Double blinding is used to decrease the placebo effect.
Determine if the statement is true or false. If it is false, rewrite it as a true statement. It is impossible for the Census Bureau to obtain all the census data about the population of the United States.
The statement is true.
Determine whether the study is an observational study or an experiment. Explain. In a survey of 1318 adults in a country, 59% said the country's leader should release all medical information that might affect their ability to serve. The study is _____, because _____
The study is observational, because it does not apply a treatment to the adults.
Determine whether the data set is a population or a sample. Explain your reasoning. The salary of 8 teachers in a school.
This is a sample, because it is a collection of salaries for some teachers in the school.
A polling organization contacts 2894 undergraduates who attend a college and live outside the United States and asks whether or not they had taken a course in conversational English during their studies. What is the population in the study? What is the sample in the study?
Undergraduates who attend a college and live outside the United States The 2894 undergraduates who attend a college and live outside the United States.
A statistic is a numerical description of a
sample characteristic
Determine whether the underlined value is a parameter or a statistic. Telephone interviews of 1,502 adults 18 years of age or older found that only 69% could identify the current vice-president. Is the value a parameter or a statistic?
statistic
Determine whether the underlined numerical value is a parameter or a statistic. Explain your reasoning. In a survey of a sample of 1050 teenagers, 17% said they like to watch soccer.
statistic, because the data set of a sample of 1050 teenagers is a sample
Determine whether the variable is qualitative or quantitative. Explain your reasoning. Postal ZIP codes The variable is _____ because ZIP codes are _____
the variable is qualitative because zip codes are attributes or labels
Suppose a survey of 926 homeowners found that more than 26% bought flood insurance. Which part of the survey represents the descriptive branch of statistics? Make an inference based on the results of the survey. Choose the best statement of the descriptive statistic in the problem. Choose the best inference from the given information.
26% of homeowners in the sample bought flood insurance. Most homeowners do not buy flood insurance.
Suppose a survey of 530 women in the United States found that more than 63% are the primary investor in their household. Which part of the survey represents the descriptive branch of statistics? Make an inference based on the results of the survey. Choose the best statement of the descriptive statistic in the problem. Choose the best inference from the given information.
63% of women in the sample are the primary investor in their household. There is an association between U.S. women and being the primary investor in their household.
Determine whether the data set is a population or a sample. Explain your reasoning. The salary of each baseball player in a league.
Population, because it is a collection of salaries for all baseball players in the
Determine whether the data set is a population or a sample. Explain your reasoning. A survey of 500 spectators from a stadium with 42,000 spectators
Sample, because the collection of 500 spectators' surveys is a subset of all spectators in the stadium
