Warm-up ① 5+3(x – 6) – 7x ② -3n(n – 5) ③ -(-3y + 5) + 2y – 13 ④ Order the numbers for least to greatest. ⑤ Evaluate when x = – 4 and y = – – (–x) + |y|

Surveys & Samples Lesson 13.5 Page 871

Vocabulary Survey – a study of one or more characteristics of a group. Survey – a study of one or more characteristics of a group. Population – the entire group you want information about Population – the entire group you want information about Students of the school Students of the school People who eat at McDonalds People who eat at McDonalds Sample – part of the population Sample – part of the population 100 students 100 students 1,000 customers 1,000 customers

Sampling Methods Random – every member of the population has an equal chance of being selected Random – every member of the population has an equal chance of being selected Stratified Random – population is divided into distinct groups and members are selected randomly from each group Stratified Random – population is divided into distinct groups and members are selected randomly from each group Students at the school are divided by class and then 50 students are randomly selected from each class Students at the school are divided by class and then 50 students are randomly selected from each class

Sampling Methods Systematic – a rule is used to select members Systematic – a rule is used to select members Every 10 students to enter the school building Every 10 students to enter the school building Convenience - only members that are easily accessible are selected Convenience - only members that are easily accessible are selected Students that are in a rooms Students that are in a rooms Self-selected – members volunteer themselves Self-selected – members volunteer themselves Students complete a survey card and return it to the office Students complete a survey card and return it to the office

Biased Biased sample – a sample that is not representative; parts of the population may be over-represented or under-represented Biased sample – a sample that is not representative; parts of the population may be over-represented or under-represented Biased question – a question that encourages a particular response Biased question – a question that encourages a particular response Survey questions should be worded to avoid bias Survey questions should be worded to avoid bias Is it bias? Is it bias? Do you like delicious ice cream or boring broccoli? Do you like Pepsi or Coke?

Time to Practice With a partner complete problems 1, 3-11 and on pages in your book. With a partner complete problems 1, 3-11 and on pages in your book. Each person needs to have their own paper to turn in. Each person needs to have their own paper to turn in. You have 10 minutes to complete this. Don’t waste time! You have 10 minutes to complete this. Don’t waste time!