text: import pandas as pd 
  import numpy as np
  
  def average(df):
      df["sumGrades"] = df["Grade"] * df["Users"]
      total_users = np.sum(df["Users"])
      total_grade = np.sum(df["sumGrades"])
  
      return total_grade/total_users
  def gradeStats(filename='grades.csv'):
      df = pd.read_csv(filename)
  
      print(f"Average is: {average(df)}")
  
  
  if __name__ == "__main__":
      gradeStats()