Get a random number focused on center

Question

Is it possible to get a random number between 1-100 and keep the results mainly within the 40-60 range? I mean, it will go out of that range rarely, but I want it to be main

Answer 1

You can use a helper random number to whether generate random numbers in 40-60 or 1-100:

// 90% of random numbers should be between 40 to 60.
var weight_percentage = 90;

var focuse_on_center = ( (Math.random() * 100) < weight_percentage );

if(focuse_on_center)
{
	// generate a random number within the 40-60 range.
	alert (40 + Math.random() * 20 + 1);
}
else
{
	// generate a random number within the 1-100 range.
	alert (Math.random() * 100 + 1);
}