Average Days to Ship

Return the average number of days between ordered_at and shipped_at for shipped orders, rounded to 2 decimals.

Table schema

Orders(id INT PRIMARY KEY, ordered_at DATE, shipped_at DATE, delivered_at DATE)

Sample data

id | ordered_at | shipped_at | delivered_at
1 | 2026-05-01 | 2026-05-02 | 2026-05-05
2 | 2026-05-02 | 2026-05-06 | 2026-05-12
3 | 2026-05-03 | 2026-05-04 | NULL
4 | 2026-05-04 | NULL | NULL
5 | 2026-05-08 | NULL | NULL