1. Honors Advanced Algebra Presentation 1-3 SAMPLING METHODS

2.  EQ: How do I determine if my sampling method is unbiased?  MCC9-12.S.IC.3 Recognize the purposes of and differences among sample surveys, experiments, and observational studies; explain how randomization relates to each ESSENTIAL QUESTION AND STANDARDS

3.  Sample – a portion of the population.  Population – the entire group that is being studied.  Statistic – a number that describes a sample.  Parameter – a number that describes the population.  Survey – a study of a sample of the population used to predict characteristics of the entire population.  Census – a study of the entire population. VOCABULARY

4.  Unbiased sample - a random sample that is representative of the population.  Underrepresented sample – a sample where one or more groups of the population are omitted.  Overrepresented sample – a sample where one or more groups has a greater representation than in the general population. BIASED VS UNBIASED SAMPLES

5. Name: Random Sample Method: Every member of the population has an equal likelihood of being chosen. Examples: Assign everyone a number and have a random number generator pick numbers. OR Put every person’s name in a hat and pick out names. TYPES OF SAMPLES

6. Name: Systematic Sample Method: Pick sample participants based on a rule. Examples: Choose every 5 th person who walks through the door. OR Ask everyone whose last name begins with M. TYPES OF SAMPLES

7. Name: Convenience Sample Method: Pick sample participants based on who is available. Examples: Choose the first 10 people you see when you enter your next class. OR Choose the friends that you are meeting after school. TYPES OF SAMPLES

8. Name: Self-Selected Sample Method: Participants choose to be included in the sample Examples: Put out a survey at the front desk for guests to fill out. OR Offer shoppers a discount for going online to answer a survey. TYPES OF SAMPLES

9. Name: Stratified Random Sample Method: The population is divided into groups. Each member of each group has an equal chance of being chosen. Examples: Choose 10 males and 10 females to participate. OR Choose 20 people born in each decade from 1950- 2009. TYPES OF SAMPLES

10.  What is the population and what is the sample? A car factory just manufactured a load of 6,000 cars. The quality control team randomly chooses 60 cars and tests the air conditioners. They discover that 2 of the air conditioners do not work. Population: 6,000 cars Sample: 60 cars SAMPLE OR POPULATION?

11.  What is the population and what is the sample? In a survey of 40 employees at a company, 18 said they were unhappy with their pay. The company has 180 employees. Population: 180 employees Sample: 40 employees SAMPLE OR POPULATION?

12.  Call 100 random people listed in the phone book to ask how long they’ve been living in their home:, Ask every 10th person at a school off of a complete roster about how many courses they are taking:, Ask 25 families eating at a restaurant on a Tuesday night about how often they eat out:, Out of each class at school, ask a number of students proportional to the number of students in each class how much they enjoyed homecoming:, BIASED OR UNBIASED? TYPE OF SAMPLE? Biased Random Sample Unbiased Systematic Sample Biased Convenience Sample UnbiasedStratified Random Sample

13.  Pg. 20-21, #14-25 HOMEWORK