How can you tell when to use a discrete graph as opposed to using a continoous graph?

Use a discrete graph when you are dealing with distinct, separate values, such as counts of items or events that cannot be divided further, like the number of students in a class. In contrast, a continuous graph is appropriate for data that can take on any value within a range, such as temperature or time, where measurements can be infinitely precise. Essentially, if the data points are countable and finite, choose a discrete graph; if they can vary smoothly and infinitely, opt for a continuous graph.