Euler Problem 30

My attempt to solve Project Euler no. 30 in Ruby

a = 1..9999

def ret_sum_of_power(number)
  numbers_array = number.to_a
  my_total = 0
  numbers_array.each do |my_num|
    my_total = my_total + my_num ** 4
  end
  return my_total
end

a.each do |my_a|
  if ret_sum_of_power(my_a) == my_a
    puts my_a
  end
end