Final answer:
A trend line in a release burn-down chart indicates the projected progress over time by showing the amount of work remaining, aiding in prediction of project completion.
Step-by-step explanation:
A trend line through a release burn-down chart is used to visualize progress and indicate the projected progress over time. This trend line shows how much work is remaining in a project or sprint, and it can help predict when the work will be completed if the current pace is maintained. The release burn-down chart itself does not directly show the number of tasks completed or the team's velocity, but rather the amount of work that still needs to be done.
These charts are key in project management for visualizing and managing the progress of projects in an agile framework. They reflect the total work left to do versus the time that is left for the sprint or release. The downward slope of the trend line in a release burn-down chart indicates that work is being completed and the project is moving towards its goal.