6.6 Analyze Surveys 6.6 Analyze Surveys and Samplesand Samples

6.6 Analyze Surveys 6.6 Analyze Surveys and Samplesand Samples

MM1D3c: Understand that a random MM1D3c: Understand that a random sample is used to improve the chance sample is used to improve the chance of selecting a representative sample.of selecting a representative sample.

Unit 4: The Chance of Winning!

Vocabulary• Survey- A study of one or more characteristics of a

group.

• Population- The entire group you want information about.

• Representative sample- A sample that accurately reflects the characteristics of a population.

• Bias sample- A sample that is not representative of the population.

• Bias question- A question that encourages a particular response.

Vocabulary: Types of sampling

• Random sample- Every member of the population has an equal chance of being selected.

• Stratified random sample- The population is divided into distinct groups. Members are selected at random from each group.

• Systematic sample- A rule is used to select members of a population.

• Convenience sample- Only members of the population who are easily accessible are selected.

• Self-selected sample- Members of the population select themselves by volunteering.

(Ex 1) Classify a sampling method

A high school is conducting a survey to determine the average number of hours that their students spend doing homework each week. At the school, only the members of the sophomore class are chosen to complete the survey. Identify the populations and classify the sampling method.

(Ex 2) Identify a potentially biased sample

Is the sampling method used in Example 1 likely to result in a biased sample? Why or why not?

(Ex 3) Identify potentially biased questions

Tell whether the question is potentially biased. Explain your answer. If the question is potentially biased, rewrite it so that it is not.

a) Do you still support the school basketball team, even though the team is having its worst season in 5 years?

(Ex 4) Identify potentially biased questions

Tell whether the question is potentially biased. Explain your answer. If the question is potentially biased, rewrite it so that it is not.

a) Don’t you think that dogs are better pets than cats?

Checkpoint5) In Example 1, suppose the

school asks students to volunteer to take the survey. Classify the sampling method? (Is this sampling method likely to result in a bias sample?)

6) An amusement park owner wants to evaluate the customer service given by the park’s ride operators. One day, every 10th customer leaving the park was asked, “Do you think that our friendly, well-trained ride operators provided excellent customer service today?”

a) Is this sampling method likely to result in a biased sample? Explain.

b) Is this question potentially biased? Explain your answer. If so, rewrite it so that it is not.

Assignment: p. 361 #1-11