Some activities provide a graph that you can change using your mouse. Here is a simple guide to what you can usually do with these graphs. Either click on the arrows at each end or drag the central rectangle. This will cause the graph to change in some way. Left button click ...Zooms in Shift & left button click... Zooms out Left button click - hold - drag - release... Drag a window which is then zoomed in on Right button click - hold - drag...Move the whole graph