#   This is pseudocode. It is mostly in English.
#   You have to translate it into Perl.
#   
#   Here are the variables you need:
#
#   data (an array with the numbers)
#   sorted data (an array with the sorted numbers)
#   number (the number you are reading from the user; a scalar)
#   number of items
#   sum (a scalar, holds the total of all the numbers)
#   average (a scalar)
#   median  (a scalar)
#   percentage  (how far above or below the average a score is; scalar)
#   item (a scalar used as a loop variable)

#
#   read in the data

prompt for a number
read number and chomp it
while (number != -1)
{
	if (number > 0)
	{
		use push to add the number to the end of the data array
	}
	else
	{
		output an error message; the number must be positive
	}
	prompt for a number
	read number and chomp it
}

number of items = scalar(@data array)
if (number of items is greater than zero)
{
	# calculate the average
	set sum to zero
	for each item in the data array
	{
		add item to sum
	}
	average = sum / number of items
	
	# calculate the median
	# remember to use the sorted data array in the formula!
	sorted data array = sort(data array)
	if (number of items % 2 == 1)
	{
		use formula in the assignment to calculate median for odd number of items
	}
	else
	{
		use formula in the assignment to calculate median for even number of items
	}
	
	output the average, properly labeled
	output the median, properly labeled
	
	# now print out the scores and their relation to the average
	print "Value     % above/below average\n";  # the heading
	
	for each item in the data array
	{
		if (item is greater than average)
		{
			percent = 100 * (item - average) / average;
			print "$item  $percent% above\n";
		}
		elsif (item is less than average)
		{
			percent = 100 * (average - item) / average;
			print "$item   $percent% below\n";
		}
		else
		{
			print "$item   0% exactly average\n";
		} 
	}
}
else
{
	output a message that says no data was entered
}