Cancellation Rate by Rider City
Ops suspects cancellation behavior differs by city and wants a rate, not a raw count, so cities of different sizes are comparable.
riders
| id | name | city | signup_date |
|---|---|---|---|
| 1 | Maya Chen | Austin | 2023-01-05 |
| 2 | Noah Patel | Denver | 2023-02-14 |
| 3 | Zara Ahmed | Austin | 2023-03-01 |
| 4 | Leo Kim | Seattle | 2023-04-20 |
| 5 | Ivy Brooks | Denver | 2023-05-11 |
rides
| id | rider_id | driver_id | distance_km | fare | ride_date | status |
|---|---|---|---|---|---|---|
| 1 | 1 | 1 | 5.2 | 12.5 | 2023-06-01 | completed |
| 2 | 1 | 4 | 3 | 8 | 2023-06-03 | completed |
| 3 | 2 | 2 | 10 | 22 | 2023-06-02 | completed |
| 4 | 3 | 1 | 2.1 | 6.5 | 2023-06-05 | cancelled |
| 5 | 3 | 4 | 4.4 | 11 | 2023-06-06 | completed |
| 6 | 4 | 3 | 7.8 | 18 | 2023-06-04 | completed |
| 7 | 5 | 2 | 1.5 | 5 | 2023-06-07 | cancelled |
| 8 | 2 | 2 | 12.3 | 26.5 | 2023-06-10 | completed |
| 9 | 1 | 1 | 6.6 | 15 | 2023-06-12 | completed |
| 10 | 4 | 3 | 3.3 | 9 | 2023-06-15 | completed |
| 11 | 5 | 2 | 8.8 | 19.5 | 2023-06-18 | completed |
| 12 | 3 | 4 | 2.9 | 7.5 | 2023-06-20 | cancelled |
Task: Write a query that returns one row per rider city with its cancellation_rate: out of all rides booked by riders who live in that city, the fraction that ended up cancelled, as a number between 0 and 1 rounded to 2 decimals. Every ride counts toward the denominator whatever its status; the city is the rider's home city, not the driver's; and a city with no cancellations at all still appears, at 0. Rows come back in alphabetical order of city.
Example output — shape only, on invented cities and rates; a city that never cancelled still shows up, at 0.
| city | cancellation_rate |
|---|---|
| Boise | 0.4 |
| Reno | 0 |
| Tulsa | 0.17 |
Sign in to solve this problem
Reading problems is free for everyone — solving them (Run, Submit, and tracking what you've solved) needs an account.
Sign in