Draw your own data tool
Sometimes it is nice to be able to make up a set of data to explore. Here is a cool tool that makes it easy to craft your own data set: just draw the data and you will instantly see how each new data point affects the mean, standard deviation, and Pearson’s r. You can even download the data you have created. A nice tool to explore, it could be especially handy for instructors who need to make quiz and test items. The page was developed by stats guru Robert Grant.