**Assignment
#12**

Explorations with Excel

By

**Michelle
Nichols**

**STAMPS
and their Increasing Costs**

The cost of stamps are always
increasing. How can we determine when
the next rise will be? When will the
cost of a first class postage stamp reach $1.00? When the cost be 64 cents? How soon should we expect the next 3 cent
increase? How do we determine data like
this? Start by observing the data set
below, based on the first class letter postage for the US Mail from 1933 to
1996.

Year |
Rate (in cents) |

1919 |
2 |

1932 |
3 |

1958 |
4 |

1963 |
5 |

1968 |
6 |

1971 |
8 |

1974 |
10 |

1975 |
13 |

1978 |
15 |

1981 |
20 |

1985 |
22 |

1988 |
25 |

1991 |
29 |

1994 |
32 |

1997 |
33 |

1999 |
34 |

2002 |
37 |

We can graph this data in Excel to better picture the
increase.

The data has been graphed with the equation using the
power function, and our R^{2} calculation.