# Exercise 4：571.Find Median Given Frequency of Numbers

## 1 Description

TThe `Numbers` table keeps the value of number and its frequency.

```
+----------+-------------+
|  Number  |  Frequency  |
+----------+-------------|
|  0       |  7          |
|  1       |  1          |
|  2       |  3          |
|  3       |  1          |
+----------+-------------+
```

In this table, the numbers are `0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 2, 3`, so the median is `(0 + 0) / 2 = 0`.

```
+--------+
| median |
+--------|
| 0.0000 |
+--------+
```

Write a query to find the median of all numbers and name the result as `median`.

## 2 Create Table and insert into values

```sql
create table if not exists leetcode.ex_571_number
(
 number int, 
 frequency int
)  stored as orc ;

INSERT INTO table leetcode.ex_571_number  VALUES
('0' , '7' ),
('1' , '1' ),
('2' , '3' ),
('3' , '1' )

```

{% hint style="info" %}

{% endhint %}