Solution: Use a stats module

Here is a possible solution to the task.

Code

The program, stats.raku:

use Stats;

my @scores = 10, 20, 30, 40;

say "total: { total(@scores) }";
say "mean: { mean(@scores) }";

🦋 You can find both source files in the exercises/advanced/modules-basics/stats-module directory.

$ raku -I. stats.raku
total: 100
mean: 25

A single use Stats brings in both exported subroutines at once — use imports everything the module marks with is export, not just one name.
mean calls total inside the module. The program never calls total on its own behalf there, yet it still works: a module’s subroutines can rely on one another, and the caller only sees the exported names.
With four numbers adding to 100, the mean is 100 / 4, which is 25.