**Vocabulary**

population, representative, sample

**TEKS** 8(1)(A), 8(1)(D), 8(11)(G), 8(11)(C)

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

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:

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:

**TEKS** 8(1)(A), 8(1)(D), 8(11)(C)

**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.

Digits, Grade 8, Volume 2, Homework Helper
Unit D: Two-Dimensional Shapes
Unit E: Measurement and Data
Math Symbols
Formulas Measures
Properties

Topic 11: Scatter Plots
Topic 12: Samples

Unit F: Personal Financial Literacy
Unit G: Step-Up Lessons
- 11-1: Interpreting a Scatter Plot
- 11-1: TEKS Practice
- 11-2: Constructing a Scatter Plot
- 11-2: TEKS Practice
- 11-3: Investigating Patterns – Association
- 11-3: TEKS Practice
- 11-4: Linear Models – Fitting a Straight Line
- 11-4: TEKS Practice
- 11-5: Using the Equation of a Linear Model
- 11-5: TEKS Practice
- 11-6: Additional Problem Solving
- 11-6: TEKS Practice

Topic 15: Step-Up Lessons

English/Spanish Glossary
Formulas
- 15-1: Solving Equations Using the Distributive Property
- 15-1: TEKS Practice
- 15-2: Solutions – One, None, or Infinitely Many
- 15-2: TEKS Practice
- 15-3: Exponents and Multiplication
- 15-3: TEKS Practice
- 15-4: Exponents and Division
- 15-4: TEKS Practice
- 15-5: Operations with Numbers Expressed in Scientific Notation
- 15-5: TEKS Practice
- 15-6: Solving Simultaneous Linear Equations Using Addition
- 15-6: TEKS Practice
- 15-7: Solving Simultaneous Linear Equations Using Subtraction
- 15-7: TEKS Practice