<p>Table: <code>Prices</code></p> <pre> +---------------+---------+ | Column Name | Type | +---------------+---------+ | product_id | int | | start_date | date | | end_date | date | | price | int | +---------------+---------+ (product_id, start_date, end_date) is the primary key (combination of columns with unique values) for this table. Each row of this table indicates the price of the product_id in the period from start_date to end_date. For each product_id there will be no two overlapping periods. That means there will be no two intersecting periods for the same product_id. </pre> <p> </p> <p>Table: <code>UnitsSold</code></p> <pre> +---------------+---------+ | Column Name | Type | +---------------+---------+ | product_id | int | | purchase_date | date | | units | int | +---------------+---------+ This table may contain duplicate rows. Each row of this table indicates the date, units, and product_id of each product sold. </pre> <p> </p> <p>Write a solution to find the average selling price for each product. <code>average_price</code> should be <strong>rounded to 2 decimal places</strong>.</p> <p>Return the result table in <strong>any order</strong>.</p> <p>The result format is in the following example.</p> <p> </p> <p><strong class="example">Example 1:</strong></p> <pre> <strong>Input:</strong> Prices table: +------------+------------+------------+--------+ | product_id | start_date | end_date | price | +------------+------------+------------+--------+ | 1 | 2019-02-17 | 2019-02-28 | 5 | | 1 | 2019-03-01 | 2019-03-22 | 20 | | 2 | 2019-02-01 | 2019-02-20 | 15 | | 2 | 2019-02-21 | 2019-03-31 | 30 | +------------+------------+------------+--------+ UnitsSold table: +------------+---------------+-------+ | product_id | purchase_date | units | +------------+---------------+-------+ | 1 | 2019-02-25 | 100 | | 1 | 2019-03-01 | 15 | | 2 | 2019-02-10 | 200 | | 2 | 2019-03-22 | 30 | +------------+---------------+-------+ <strong>Output:</strong> +------------+---------------+ | product_id | average_price | +------------+---------------+ | 1 | 6.96 | | 2 | 16.96 | +------------+---------------+ <strong>Explanation:</strong> Average selling price = Total Price of Product / Number of products sold. Average selling price for product 1 = ((100 * 5) + (15 * 20)) / 115 = 6.96 Average selling price for product 2 = ((200 * 15) + (30 * 30)) / 230 = 16.96 </pre>