$4.$ arrayAverage function

a$)$ Write a function named arrayAverage that accepts an array of numbers and returns the average of those numbers.

b$)$ Run the test shown below in the console to verify your function works properly.

$//$ Test

let values $=[31\mathrm{.}9,31\mathrm{.}3,42\mathrm{.}4,42\mathrm{.}4,60\mathrm{.}8,28\mathrm{.}1]$; console.log$($arrayAverage$($values$))$; $//$expect $39\mathrm{.}48333...$

c$)$ Add code in your JavaScript file to call the arrayAverage function with an argument of $[31\mathrm{.}9,31\mathrm{.}3,42\mathrm{.}4,42\mathrm{.}4,60\mathrm{.}8,28\mathrm{.}1]$ and displays what it returns in the textarea of the web page by concatenating to the textarea value.