---
id: 5d792539ec758d45a6900173
title: Part 125
challengeType: 0
dashedName: part-125
---
# --description--
The `length` property returns the length of an array. Use this property with the `sum` function to define an `average` function.
As with `sum`, add this function to both the global scope and to `spreadsheetFunctions`.
# --hints--
See description above for instructions.
```js
assert(
average([1, 5, 12]) === 6 && spreadsheetFunctions.average([1, 20, 3, 8]) === 8
);
```
# --seed--
## --before-user-code--
```html
Spreadsheet
```
## --after-user-code--
```html
```
## --seed-contents--
```html
```
# --solutions--
```html
```