How to Solve Confirmation Rate Problem

Table: Signups +----------------+----------+ | Column Name | Type | +----------------+----------+ | user_id | int | | time_stamp | datetime | +----------------+----------+ user_id is the column of unique values for this table. Each row contains information about the signup time for the user with ID user_id. Table: Confirmations +----------------+----------+ | Column Name | Type | +----------------+----------+ | user_id | int | | time_stamp | datetime | | action | ENUM | +----------------+----------+ (user_id, time_stamp) is the primary key (combination of columns with unique values) for this table. user_id is a foreign key (reference column) to the Signups table. action is an ENUM (category) of the type ('confirmed', 'timeout') Each row of this table indicates that the user with ID user_id requested a confirmation message at time_stamp and that confirmation message was either confirmed ('confirmed') or expired without confirming ('timeout'). The confirmation rate of a user is the number of 'confirmed' messages divided by the total number of requested confirmation messages. The confirmation rate of a user that did not request any confirmation messages is 0. Round the confirmation rate to two decimal places. Write a solution to find the confirmation rate of each user. Return the result table in any order. The result format is in the following example.