To do this you first need to make sure that the layer containing the axis scale you want applied to other layers is the parent layer (lowest layer number). If this layer containing the axis scale is of a higher layer number and because of the fact that you want its scale to be applied to all the other layers in the graph window you will want to ensure that this layer is layer number 1. If it is not simply open the script window (menu option: Window:Script Window) and use the following Labtalk command: page.reorder(Layer2,Layer1);
This command assumes that the layer whose axis scale you want applied to the others is presently layer 2 and points it to be assigned as layer 1, so the exact syntax to be used would be:
page.reorder(2,1) [ENTER]
You can then link the child layers to the parent layer. To link a child layer (i.e., layer 2) to the parent layer (layer 1) double-click on the layer 2 icon (the 2 in the gray box in the upper left hand corner of the graph window) then go to "Layer Properties". Select 'Layer 1' for the 'Link to' setting. Then click the 'Link Axes' button to go to the Link Axes Scale dialog box. You would select 'Straight (1 to 1)' for the X and/or Y axis link. Click OK. Your axis scale(s) are now linked with a one to one relationship. Don't forget that whenever you rescale your axes that you must do it within the parent layer such that all the child layers will update accordingly.