# $average

Returns the average value of a set of values, excluding $Null values.

### Syntax

$average(*expression*)

### Parameters

*expression* |
any expression |

### Return Value

Number, with the number of decimal places implied by *expression*.

### Comments

The function calculates the average of a set of values, excluding $Null values.

*Expression* is often a WHERE expression that includes only selected values in the averaging operation. If the WHERE expression (expr1 WHERE expr2) is true, the expr1 value is included in the averaging operation; otherwise, *expression* is considered $Null and is not included in the averaging operation.

### Example

compute Employees where DeptName="Sales" \

evaluate (let AvgAge = $average($year($date)-$year(BirthDate)))

(let AvgSal = $average(Salary where Sex = "F"))

Finds the average age of all employees, and the average salary of all female employees, in the sales department.

report footing \

$average(Salary) \

($total(Salary*Salary) / $count(Salary) - $average(Salary) * $average(Salary))

Reports average salary and salary variance.