Moving an element retrieving values from dragged one

Moving an element retrieving values from dragged one

Hi there, I'm moving an element using the draggable UI from jquery.
With the drag event I get the left value of the element dinamically while I do the dragging. Afterwords, I use animate to give this values to the left css value of another element so it moves as much as the dragged one.
This works fine, but I would like this element to move at a different speed than the dragged...
Sounds easy but:
Let's say I want the second element to move 1'5 pixels for every pixel the dragged one moves, this seems to be as simple as multiplying:
function onDrag()
{
var moving = #('dragged').offset().left*1.5;
$('#moveme').animate({'left' : (moving) + 'px'}, 0);
}

The problem is:
When you do this, the $('#moveme') element moves exactly at the perfect spped, but it start's it's movement in the first offset().left value og $('#dragged') so there is a jump. I would like it to move at the same speed but from it's own offset().left starting position.
I can't find the way to express this in a Math's function without causing a mess. Any help?