input: from typing import List
  
  
  def predict_customer_lifetime_value(transactions: List[List[float]]) -> float:
      """ Create a machine learning model to predict customer lifetime value 
      given a customer's past transactions.
      >>> predict_customer_lifetime_value([[10.0, 100.0, 5.0]])
      1234.56
      >>> predict_customer_lifetime_value([[20.0, 50.0, 5.0]])
      5678.90
      """
output:     total_spent = sum(sum(transaction) for transaction in transactions)
      num_transactions = sum(len(transaction) for transaction in transactions)
      average_transaction_value = total_spent / num_transactions
      return round(average_transaction_value * 100, 2)