input: from typing import List
  
  def averageMatrix(matrix: List[List[int]]) -> float:
      """ Calculate the average of all elements in a given 2-dimensional array.
      >>> averageMatrix([[3,2,6],[8,5,9],[4,7,1]])
      4.77
      """
      total_sum = 0
      for row in matrix:
          for element in row:
              total_sum += element
      
      return round(total_sum / (len(matrix) * len(matrix[0])), 2)
output:     total_sum = 0
      for row in matrix:
          for element in row:
              total_sum += element
      
      return round(total_sum / (len(matrix) * len(matrix[0])), 2)