We've collected the following data points --
  - {data point of #4}
  - {data point of #1}
  - {data point of #7}
  - {data point of #8}
  - {data point of #1}

Let's find the average of these values. We've got a tally running, we 
should continue accumulating values --

  : {there are $count data points} 
    {data point of $x} {sum is $n} 
  > 
    {@add $count and #1 into &"there are * data points"} 
    {@add $n and $x into &"sum is *"} :

  : {data point of $x}
  > 
    {there are #1 data points} 
    {sum is $x} :

When we are out of data points to tabulate, we can finally compute the 
average --

  : {there are $count data points} {sum is $sum}
  >
    {@divide $sum by $count into &"the average is *"} :

Write out the finaly result to the console --

  : {the average is $average} 
  > 
    {@write "The average is "}
    {@write $average}
    {@write ".\n"} :