Rats!
Requests in category "Rodents- Rats" average over 64 days to resolve. Why?
Investigate in 4 steps:
Why is the average so high? Check the distribution of completion times. Hint:
date_trunc()can be used on intervals.See how excluding outliers influences average completion times.
Do requests made in busy months take longer to complete? Check the correlation between the average completion time and requests per month.
Compare the number of requests created per month to the number completed.
Remember: the time to resolve, or completion time, is date_completed - date_created.
This exercise is part of the course
Exploratory Data Analysis in SQL
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
-- Truncate the time to complete requests to the day
SELECT ___ AS completion_time,
-- Count requests with each truncated time
___
FROM evanston311
-- Where category is rats
WHERE category = 'Rodents- Rats'
-- Group and order by the variable of interest
GROUP BY ___
ORDER BY ___;