12-3: Representative Samples

Key Concept

You are investigating the percentage of males in the population below. The population:

Population: 12 females = 75% female. 4 males = 25% male.

In a representative sample, the number of subjects in the sample with the trait being studied is proportional to the number of members in the population with that trait.

A representative sample:

Representative sample: 6 females = 75% female, 2 males = 25% male. Accurately represents the population.

In a biased sample, the number of subjects in the sample with the trait being studied is not proportional to the number of members in the population with that trait.

A biased sample:

Biased sample: 4 females = 50% female, 4 males = 50% male. Does not accurately represent the population.

Part 1

Example Finding Representative Samples

Suppose the new music teacher wants to find out how many students in the school can play a musical instrument. Do you think each sampling method is likely to produce a representative sample of the entire school? Explain.


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Digits, Grade 8, Volume 2, Homework Helper Unit D: Two-Dimensional Shapes Unit E: Measurement and Data Unit F: Personal Financial Literacy Unit G: Step-Up Lessons English/Spanish Glossary Formulas Math Symbols Formulas Measures Properties