input: Write a function to compute standard deviation of a list of numbers.
  assert abs(compute_std_dev([12, 14, 11, 20, 13]) - 3.067) < 0.001
  assert abs(compute_std_dev([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) - 2.872) < 0.001
  assert abs(compute_std_dev([10, 20, 30, 40, 50]) - 15.811) < 0.001
output: def compute_std_dev(numbers):
      if not numbers:
          return 0.0
      mean = sum(numbers) / len(numbers)
      variance = sum((x - mean) ** 2 for x in numbers) / len(numbers)
      return variance ** 0.5