To Associate Annotation with a point right click an annotation and choose the Associate with Point option from the context menu.
Choosing the Associate with Point option causes the cursor to turn into a cross. Then a data point that is to be associated with the Annoation is chosen by clicking a data point on the chart. It is not possible to select an empty point on the chart as a point that is to be associated with an Annotation. After a data point has been chosen the cursor turns back to an arrow and a line is drawn from the Annotation to the associated point.