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0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Sometimes, these sampling methods result in biased samples.
A biased sample does not accurately represent the population. The data collected from biased samples is not reliable.
(pp 8)
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Population Sample Possible BiasPeople in thelocal area
Up to 1500 peoplewho take the survey
Not all people arein the phone book
Identifying Biased SamplesA radio station manager chooses 1500 names from the local phone book to survey people about their listening habits.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
An advice columnist asks her readers to write in with their opinions about how to hang the toilet paper on the roller.
Population Sample Possible BiasReaders of the column
Readers who write in
Only readers with strong opinions write in.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
An eighth grade student council member polls classmates about a new school mascot.
Population Sample Possible Bias
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
The United States Census Bureauconducts a survey every ten years todetermine the population of the UnitedStates. The first U.S. census taken wasin 1790. Two hundred men rode onhorseback to count the number ofpeople in each household, and datawas recorded on small scraps of paper.This census cost the government just$45,000!Until 1960, the population survey wasconducted mostly door to door. At thattime, bureau officials realized that thismethod was inefficient because thepopulation was growing rapidly andbecoming more mobile and diverse.By 1980, 90% of the census was takenby mail.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
(pp 8)
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
The percent of households with houseplants in Town A (42%) is close to the national percent. The percent of households in Town B (56%) is greater than the national percent.
Town A: # of households with plants total number of households =
Town B: # of households with plants total number of households =
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Town A: # of households with pet fish total number of households =
Town B: # of households with pet fish total number of households=
The percent of households with pet fish in Town A (25%) is close to the national percent. The percent of households in Town B (55%) is greater than the national percent.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Learn to identify sampling methods and to recognize biased samples and show understanding through class work.
Students will
Learning Objective
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Discrete and Continuous QuantitiesComparison between a continuous and discrete system
(pp 10)
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Discrete quantities you can count ex: number of people who enter the library
Continuous quantities you can measure ex: temperature of water as it is heated
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Identify each quantity as continuous or discrete.
the water level in a sink as it is being filled
the speed of a car driven from your home to the mall
the number of stars you can see
a person's weight
attendance at a football game
population of Ohio
continuous discrete
continuous
continuous
discrete
continuous
discretediscrete
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Complete(pp 11) #115page 464
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Population: deli customers; sample: Sunday’s customers; possible bias: the sample does not include weekday customers.
Population: people who attend the team’s games; sample: people other than season ticket holders
attend baseball games.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Every fifth name is called.
The sample is conveniently in the hair salon.
The teacher draws a question at random from the box.
The visitors to the web site have chosen to be in the sample.
Each study group is a randomly chosen subgroup; one person is selected at random from each one.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
Population: students;sample: students who buy the entrée; possible bias: the student who buy the entrée may be the people who like the food in the cafeteria.
Population: city residents; sample: people attending the city council meeting; possible bias: most citizens do not attend city council meetings.
Population: trees; sample: trees along the river;possible bias: the trees sampled have a better
source of water than the others.
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014
0901.2 Samples and Surveys and Discrete and Continuous Data.notebook March 07, 2014