Nik's problem, but better

heavy.rb

def heavy_decimal_count(a,b)
  (a..b).select do |number|
    chars = number.to_s.split('').collect{|x| x.to_i}
    get_avg(chars) > 7
  end
end

def get_avg(arr)
  arr.inject{|sum,x| sum + x }.to_f / arr.size
end

puts heavy_decimal_count(8675,8689)