Imagine placing a plant in the ground one day and finding that it has doubled its height just a few days later. Although it may seem incredible, this can happen with certain types of bamboo species. These members of the grass family are the fastest-growing plants in the world. One species of bamboo has been observed to grow nearly $1.5$ inches every hour. In a twenty-four hour period, this bamboo plant grows about $36$ inches or an incredible $3$ feet! A constant rate of change, such as the growth cycle of this bamboo species, is a linear function.