I too am very curious about this. In the reports, I see “average response time” with crazy numbers for some agents like between 23 to hundreds of hours and yet, these agents have 100% SLAs met!?! The definition I found in Freshdesk Support is the following:

Average response time = Total time taken to respond during the selected time period divided by the number of responses in the selected time period.

Response time is calculated for every agent response rather than for every ticket. So the average response time is the average of all responses sent during the selected time period.

The time period within Business hours would only be considered for calculating the response time metrics in the Reports.The time period that was elapsed outside Business hours is excluded while calculating metrics within the Reports tab. 

The response time does not depend upon the Status of a Ticket. 

So, if a ticket is moved to Waiting on Customer or Pending, the time spent in those statuses would also be considered for response time.

I do not understand, however, why the Status is not taken into consideration in the Average Response time. It does not make sense (to me) when it is at Pending, for instance.

I just noticed that the requester of this topic submitted his question 10 months ago, with no reply. This is disappointing. I think it is better to open a ticket with support then.