6.4 Select and draw conclusions from samples. GOAL: study different sampling methods for collecting data. Sample: subset of the population. Self-selected sample , members of a population can volunteer to be in the sample.
GOAL: study different sampling methods for collecting data.
Self-selected sample, members of a population can volunteer to be in the sample.
Systematic sample, a rule is used to select members of a population, such as selecting every other person.
Convenience Sample, easy-to-reach members of a population are selected, such as those in the first row
Random Sample, each member of a population has an equal chance of being selected
Example 1:A teacher wants to find out how many hours students studied for a history quiz. Identify the type of sample described.
Self selected Sample
Underrepresent the population
Represents the population
Tell whether each the following samples are biased or unbiased
Example 3: In a survey of 800 people, 20% said they get a haircut once per month.
Between 16.5% and 23.5%
2. Tell whether the sample in Exercise 1 is biased or unbiased. Explain.
3. In a survey of 1100 home buyers, 90% said they used a real-estate agent to research home listings. What is the margin or error? Give an interval that is likely to contain the exact percent of all home buyers who used a real-estate agent to research home listings.
Between 87% and 93%
Workbook Page 258 1-24
Homework: Textbook Page 230: 1-17