#!/usr/bin/ruby

#
## https://rosettacode.org/wiki/Averages/Arithmetic_mean
#

func avg(list) {
    list.is_a(Array) || return nil;
    list.len > 0     || return 0;
    list.sum / list.len;
}
 
say avg([Inf, Inf]);
say avg([3,1,4,1,5,9]);
say avg([1e+20, 3, 1, 4, 1, 5, 9, -1e+20]);
say avg([10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 0, 0, 0, 0.11]);
say avg([10, 20, 30, 40, 50, -100, 4.7, -1100]);