There are six cities in Story County. The county must determine where to build fire stations. The county wants to build the minimum number of fire stations needed to ensure that at least one fire station is within 15 minutes (driving time) of each city. Using the information in the following table: Formulate an integer programming model that will tell Story County how many fire sta- tions should be built and where they should be located. Use Excel to determine how this can be done at minimum cost. City Within 15 Minutes 1 1, 2 2 1, 2, 6 3, 4 3, 4, 5 4, 5, 6 2, 5, 6 3 4