You can use the .NET Framework's System.Random class to generate random numbers in a PowerShell script. To do this, you will first need to create a new object for creating random numbers, then use the objects methods to create a random number.
The following will output a nonnegative random integer number between 1 and 10:
$rand = New-Object System.Random $rand.next(1,11)
Note that the upper bound is not inclusive, so we need to make it 11 to make it possible to generate the number 10.
Floating-point numbers between 0.0 and 1.0
To generate a number between 0 and 1, you can use the NextDouble method, which will generate a number like: