To calculate velocity, we will use story points to measure the amount of work completed in each sprint.  

Step 1: Calculate how many user story points are achieved in each sprint 

In sprint 1: 

A team committed to achieving/ completing 6 user stories. 

Each user story had eight-story points, making a total commitment of 48 story points. 

The team completed three of the SIX user stories. 

In sprint 2: 

The team this time committed to eight user stories (including three user stories from the sprint 1). 

User stories had eight-story points, making a total commitment of 64 story points. 

This time team completed FIVE out of the eight user stories. 

In sprint 3: 

The team again committed to nine user stories. 

Each user story had ten-story points, making a total commitment of 80 story points. 

The team was able to complete seven of the ten user stories. 

Step 2: Average calculation of completed story points 

Add the total of story points completed, then divide by the number of sprints. 

1. Sprint 1: 3 user stories x 8 story points = 24 
2. Sprint 2: 5 user stories x 8 story points = 40 
3. Sprint 3: 7 user stories x 8 story points = 56 

Total = 120 

Average sprint velocity is 120 ÷ 3 = 40. 

The amount of work that can be completed in future sprints on an average is 40 story points. If there are in total 192 story points remaining to be completed, it can be assumed that the team would require approximately 4 more sprints to complete the user stories in the project.