program ex;
type
 ss=array[1..1000]of real;
var
 f:ss;
 n,m:longint;
 i,j,t:longint;
 ans1,ans2,temp:real;
begin
 assign(input,'stock.in');
 assign(output,'stock.out');
 reset(input);
 rewrite(output);
 readln(n);
 for i:=1 to n do read(f[i]);
 readln;
 readln(m);
 close(input);
 for i:=1 to n-1 do
  for j:=i+1 to n do
   begin
    inc(t);
    temp:=(f[j]-f[i])*m;
    if temp>0 then ans2:=ans2+1;
    if temp>ans1 then ans1:=temp;
   end;
 writeln(ans1:0:3);
 writeln(ans2/t:0:3);
 close(output);
end.