Final answer:
Analogous estimating is the method of estimating schedule activity, resources, and activity duration by comparing the current project to similar past projects to derive estimates.
Step-by-step explanation:
The method of estimating schedule activity, resources, and activity duration by asking for a copy of an existing plan is called Analogous estimating. This approach involves comparing the current project to similar past projects to derive estimates. It relies on expert judgment and experience to provide a rough idea of the time, resources, and duration required for certain activities.