var min = 3;
var max = 7;
var n;
for (var i = 0; i < 10; i++)
{
n = Math.random() * (max - min) + min;
document.write(n + "<br />");
}
/*
run
6.722737321850531
6.606430163025816
3.6566545749621513
4.694706528529381
4.129002148897234
3.974074155325747
4.659713472139972
4.019526055364357
3.975174493700944
4.255990438724478
*/