Determine the constant of variation.

Miles, x |
Gallons, y |

25 |
1 |

50 |
2 |

75 |
3 |

100 |
4 |

Compare the ratios to check for a
common ratio.

Since the ratios are the same, the function is a direct variation. The
constant of variation is

The amount a babysitter charges is shown. The relationship between the number of hours and the amount of money is linear.

Hours |
Charge |

3 |
21 |

4 |
28 |

5 |
35 |

6 |
42 |

Determine the constant of variation.

Solution: