Chapter 1.1
how is a sample related to a population?
a sample is a subset of a population.
population or sample: the ages of 13 members of a legislature.
sample, because it is a collection of ages for some members of the legislature.
population or sample: 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.
population or sample: the ages of one person per row in a cinema.
sample, because the collection of ages of one person per row is a subset of all people in the cinema.
inferential statistics involves what?
using a sample to draw conclusions about a population.
T/F: it is impossible for the census Bureau to obtain all the census data about the population of the United States.
True. it is impossible to gather information about the entire population of any country because the population is always changing.
T/F: a sample statistic will not change from sample to sample.
The statement is false. A sample statistic can change from sample to sample.
why is a sample used more often than a population?
it is usually impossible to count every single member of a population. Counting every single member of the population is called a census.
the two branches of statistics are:
descriptive statistics and inferential statistics.
descriptive statistics involves what?
organization, summarization, and display of data
a certain zoo found that 8% of its 843 animals were nocturnal. parameter or statistic?
parameter, because the data set of all 843 animals in a zoo is a population.
population or sample: the salary of each baseball player in a league.
population because it is a collection of salaries for all the baseball players in the league.
population or sample: the age of each member of the House of Representatives.
population, because it is a collection of ages for all members of the House of Representatives.
determine if population or sample: the salary of each teacher in a school.
population, because it is a collection of salaries for all teachers in the school.
population or sample: the number of children for each household in a town.
population, because it is a collection of the number of children for all households in the town.
a parameter is a numerical description of a _____ characteristic. A statistic is a numerical description of a ____ characteristic.
population, sample
a quality-control manager randomly selects 30 bottles of orange juice that were filled on April 20 to assess the calibration of the filling machine. what is the population and sample?
population- bottles of orange juice produced in the plant on April 20. sample-the 30 bottles of orange juice selected in the plant on April 20.
a survey of 12,086 men in a particular country found that 46.8% received an influenza vaccine for a recent flu season. Identify population and sample
population- the immunization status of all men in the country sample- the immunization status of the 12,086 men selected
a polling organization contacts 2445 undergraduates who attend a university and live in the United States and asks whether or not they had spent more than $200 on food in the last month. Identify population and sample
population- undergraduates who attend a university and live in the United States. sample-the 2445 undergraduates who attend a university and live in the United States
a study of 6,076 adults in public rest rooms found that 23% did not wash their hands before exiting. Is this parameter or statistic?
statistic
T/F: a statistic is a measure that describes a population characteristic
False. A statistic is a measure that describes a sample characteristic.
T/F: a population is the collection of some outcomes, responses, measurements, or counts that of interest.
False. A population is the collection of all outcomes, responses, measurements, or counts that of interest.
in a poll, 1,001 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, 47% said that they were in favor. What is the population and sample in the given problem?
Population- all men in the country. Sample- the 1,001 men selected
Suppose a survey of 578 women in the United States found that more than 70% 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.
descriptive branch- 70% of women in the sample are the primary investor in their household. inference- there is an association between US women and being the primary investor in their household.