I have a dataset with several duplicate records. I am trying to calculate an average response time to an incident. Each incident has a separate response time but where the record is duplicated the response time is also duplicated. I am dealing with this by using DISTINCT
My table calculates the total response time for each category and calculates the number of distinct records.
I calculate the average by dividing one by the other.
however since I need to calculate the 90th percentile also I checked the maths by using avg. it provides a different answer.
what is going wrong and how do I fix it please?