Final answer:
A line graph would be the best type of chart to use to tell the story about how well the math enrichment program is doing in improving performance on the standardized test.
Step-by-step explanation:
In order to tell the story about how well the math enrichment program is doing in improving performance on a standardized test, a line graph would be the best type of chart to use. A line graph allows you to plot and show the trend or progression of data over time. It can show how performance on the standardized test has changed over a period of time, providing a clear visual representation of improvement.