# Ratios, Rates, and Proportions

## Real-World Snapshots

The model of the buildings in New York City is of the actual size. In 2000, the population of New York City was about 9,314,000. Do you think the number of people per household in New York City was greater than or less than the U.S. average?

### Data File

#### American Households

Year | Number of Households | Number of People/Household |
---|---|---|

1930 | 29,905,000 | 4.11 |

1940 | 34,949,000 | 3.67 |

1950 | 43,554,000 | 3.37 |

1960 | 52,799,000 | 3.33 |

1970 | 63,401,000 | 3.14 |

1980 | 80,776,000 | 2.76 |

1990 | 93,347,000 | 2.63 |

2000 | 105,480,000 | 2.59 |

SOURCE: U.S. Census Bureau. Go to www.PHSchool.com for a data update. Web Code: abg-2041

You will use the data above in this chapter:

Real-World Snapshots On pages 286 and 287, you will solve problems involving scale models.

### Key Vocabulary

## Where You've Been

- In Chapter 3, you learned to simplify and compare fractions. You learned to express fractions as decimals.
- In Chapter 4, you learned to add, subtract, multiply, and divide fractions and mixed numbers.

## Where You're Going

- In Chapter 5, you will write ratios and unit rates. You will solve proportions and find values in similar figures, maps, and scale models.
- Applying what you learn, you will use a map to plan a trip. You will also find the scale of a model used by a special-effects artist.