1998 Ford Escort car shakes and hesitates when accelerating

Ok so a couple months ago, my old escort started having problems accelerating and driving. It seemed as if it hesitated alot and struggled to perform well.

i took it in to get repaired and the mechanic replaced the fuel filter and fuel pump. It seems as if those changes helped alot with my fuel pressure, however, it continues to shake and struggle when accelerating. The mechanic said last night when I picked up from its previous repairs "it looks like the fourth cylinder is having problems. But it is drivable enough to use this week." I am thinking the problem could have something to do with my spark plug. However, I am not sure which one is the fourth cylinder's plug.

if I were looking at the engine from under the hood, which spark plug would be the fourth cylinder?

this is a very cheesy diagram of whats under the hood but could you basicaly label the blanks of which cylinder is which.

ex: _ _ _ _ 4 3 2 1


inside of car

engine
_ _ _ _


front of car


and if possible if you dont think this is the problem, any ideas on what might be wrong?