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# The Blunder

AGGREGATION

[Question Link](https://www.hackerrank.com/challenges/the-blunder/problem?isFullScreen=false)

Samantha was tasked with calculating the average monthly salaries for all employees in the **EMPLOYEES** table, but did not realize her keyboard's  **0** key was broken until after completing the calculation. She wants your help finding the difference between her miscalculation (using salaries with any zeros removed), and the actual average salary.

Write a query calculating the amount of error (i.e. ***actual - miscalculated***:  average monthly salaries), and round it up to the next integer.

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**Input Format**

The **EMPLOYEES** table is described as follows:

![](https://s3.amazonaws.com/hr-challenge-images/12893/1443817108-adc2235c81-1.png)

**Note:**  *Salary* is per month. 

**Constraints**

1000 < Salary < 10^5

**Sample Input**

![](https://s3.amazonaws.com/hr-challenge-images/12893/1443817161-299cc6eb7f-2.png)

**Sample Output**

```
2061
```

**Explanation**

The table below shows the salaries *without zeros* as they were entered by Samantha:

![](https://s3.amazonaws.com/hr-challenge-images/12893/1443817229-eb00d44a3b-3.png)

Samantha computes an average salary of ***98.00***. The *actual* average salary is ***2159.00***.

The resulting error between the two calculations is ***2159.00 - 98.00 =  2061.00*** . Since it is equal to the integer ***2061***, it does not get rounded up.

```sql
SELECT CEIL((AVG(salary)) - (AVG(REPLACE(salary, 0, '')))) AS avg_salary 
FROM employees;
```