Refund Rate per Seller

Return each seller with sales and the percentage of their sales that were refunded, rounded to 2 decimals. Order by name.

Table schema

Sellers(id INT PRIMARY KEY, name VARCHAR(10), joined DATE)
Sales(id INT PRIMARY KEY, seller_id INT, amount INT, refunded INT)

Sample data

Sellers
id | name | joined
1 | ShopA | 2025-01-01
2 | ShopB | 2025-06-01
3 | ShopC | 2026-02-01

Sales
id | seller_id | amount | refunded
1 | 1 | 100 | 0
2 | 1 | 200 | 1
3 | 2 | 150 | 0
4 | 2 | 50 | 0
5 | 2 | 70 | 1