How to set all selected vertices to height of another vertex? Let's say i have selected all these vertices which you can see in this screenshot, and i want to set the height to the same height as the marked vertex (see red arrow in screenshot)



I always copy the height from the target vertex, then i select each vertex one by one and paste the height into it.  But this takes a very long time, especially if you have big models. Is there an easier way to do this?

Result should look like this:
One way to do this is to set the pivot point for transforms to be the active element, by choosing Active Element for the Pivot Point in the bar below the 3D View:



If you have Pie Menus enabled, you can press .>7 instead.

Then select all the vertices you want to affect making sure that the one whose height you want to copy is the active one (i.e. select it last) and just Scale in the Z axis direction to 0, by pressing S, then Z and then 0.