Find the constant of variation from a table

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 table shows the number of gallons of paints Mrs. Robinson used to paint the number of rooms.

Number of gallons of paint |
Number of rooms painted |

2 |
18 |

3 |
27 |

4 |
36 |

5 |
45 |

The relationship between the gallons of paint and the number of rooms painted is linear.

Determine the constant of variation.

Solution: