
| Fraction | Decimal | Percentage |
| 1/2 | 0.5 | 50% |
| 1/3 | ||
| 25% | ||
| 0.2 | ||
| 1/8 | 12.5% | |
| 0.667 | ||
| 0.75 |
| 1 | |
| 0.1 | 0.9 |
| 0.23 | |
| 0.5 | |
| 0.78 | |
| 0.91 | |
| 0.85 | |
| 0.48 |
| Number Surveyed | Number of “Yes” Responses | Fraction | |
| 100 | 20 | 20/100 | 0.2 |
| 100 | 40 | ||
| 100 | 80 | ||
| 50 | 20 | ||
| 500 | 20 | ||
| 1000 | 20 |
| Appropriate?
(Yes or no) |
||
| 50 | 0.3 | |
| 50 | 0.05 | |
| 15 | 0.45 | |
| 100 | 0.01 | |
| 40 | 0.25 | |
| 80 | 0.25 |
| Sample Size | Mean | Minimum | Maximum |
| 50 | |||
| 100 | |||
| 500 |
| Sample Size | # of Successes | Point Estimate | Margin of Error |
| 100 | 30 | ||
| 1,000 | 300 | ||
| 10,000 | 3,000 |
| Appropriate?
(Yes or no) |
||
| 50 | 0.1 | |
| 100 | 0.1 | |
| 45 | 0.5 | |
| 30 | 0.5 | |
| 25 | 0.9 | |
| 120 | 0.9 |
| Confidence Level | Margin of Error | Minimum Sample Size |
| 95% | ±2.5% | |
| 95% | ±4% | |
| 95% | ±6% | |
| 99% | ±6% |
| Confidence Level | Margin of Error | Population Proportion | Minimum Sample Size |
| 95% | ±2.5% | 0.1 | |
| 95% | ±4% | 0.2 | |
| 95% | ±6% | 0.3 | |
| 99% | ±6% | 0.3 |
| Skill or Concept: I can . . . | Questions to check your understanding | Rating from 1 to 5 |
| Understand how sample size affects margin of error. | 1–4 | |
| Determine the sample size needed to achieve a given margin of error when working with proportions. | 5–7 | |
| Bring the “Looking Ahead” information to class. | 8, 9 |

| party_id | major_party | regular_voter |
| Democrat | Yes | Yes |
| Other | No | Yes |
| Democrat | Yes | No |
| Democrat | Yes | No |
| Republican | Yes | Yes |
| Other | No | No |
| Republican | Yes | Yes |
| Democrat | Yes | Yes |
| Republican | Yes | Yes |
| Other | No | Yes |
| Republican | Yes | No |
| Democrat | Yes | No |
| Republican | Yes | No |
| Other | No | No |
| Republican | Yes | Yes |
| is_liberal | |
| No | Yes |
| No | No |
| No | No |
| No | No |
| No | Yes |
| No | Yes |
| No | No |
| No | Yes |
| No | Yes |
| No | No |
| No | No |
| No | Yes |
| No | No |
| No | No |
| No | No |
| Skill or Concept: I can . . . | Questions to check your understanding | Rating from 1 to 5 |
| Identify the sample and population. | 1, Parts A and B | |
| Calculate sample proportions and their differences. | 1, Parts C and D
3 |
|
| Identify independent vs. dependent samples. | 3, 4 | |
| Use technology to calculate the confidence interval for the difference in two proportions from independent samples. | 5 | |
| Interpret the confidence interval in the context of the data. | 6 |