Pascal - Passing Arrays as Subprogram Arguments

Pascal allows passing arrays as subprogram parameters. Following function will take an array as an argument and return average of the numbers passed through the array as follows:

program arrayToFunction;
const
   size =5;
type
   a = array [1..size] of integer;
var
   balance:  a =(1000,2,3,17,50);
   average: real;  
function avg(var arr: a): real;
var
   i :1..size;
   sum: integer;
begin
   sum :=0;
   for i :=1 to size do
      sum := sum + arr[i];
   avg := sum / size;
end;
begin  
   (*  Passing the array to the function  *)
   average := avg( balance );
   (* output the returned value *)
   writeln('Average value is: ', average:7:2);
end.
 

When the above code is compiled and executed, it produces following result:

Average value is: 214.40