For the graph to represent your data most effectively, consider the following guidelines.
- The sample size should be greater than 20
- If you are trying to visualize the fit of the distribution line to your data, a sample size of less than 20 may be difficult to evaluate.
- The sample data should be selected randomly
- In statistics, random samples are used to make generalizations, or inferences, about a population. If your data were not collected randomly, your results may not represent the population.