You need Adobe Flash to play this content. Mobile devices do not support Adobe Flash.
To play this content on a computer, install and enable Adobe Flash Player for your browser.
It's amazing what can be expressed on a graph – such as, the tastiness of lemonade!
This short walkthrough will help you grasp what you need to read graphs, from the relationship of the x and y axes to the importance of labeling.
Whether and when to fertilize grass becomes clear once you see a dose-response curve.