I recommend three things:

1. Fix your compilation errors
2. Fix your runtime errors
3. Fix your logic errors

I could give more specific help if you would give a more specific problem statement than "I do not seem to accomplish that."

When I try to run your code under Perl 5.32.1 I get

Experimental push on scalar is now forbidden at fubar.new line 32, nea
+r "$avgX )"
Experimental push on scalar is now forbidden at fubar.new line 33, nea
+r "$avgY )"
Experimental push on scalar is now forbidden at fubar.new line 34, nea
+r "$avgZ )"
Experimental push on scalar is now forbidden at fubar.new line 35, nea
+r "$difF )"
Execution of fubar.new aborted due to compilation errors.
[download]

Is this what you are seeing? A different version of Perl might actually compile this, in which case it is on to the next problem.