input: Write a python function to plot a bar graph using matplotlib for given x and y axis values, with appropriate labels and title. 
  assert plot_bar_graph([1, 2, 3, 4, 5], [20, 30, 35, 38, 45], 'Months', 'Amount', 'Company Sales Over Last 5 Months')==None 
  assert plot_bar_graph(['Jan', 'Feb', 'Mar', 'Apr', 'May'], [100, 150, 200, 250, 300], 'Months', 'Sales', 'Monthly Sales Report')==None
output: import matplotlib.pyplot as plt
  
  def plot_bar_graph(x, y, xlabel, ylabel, title):
      plt.bar(x, y)
      plt.xlabel(xlabel)
      plt.ylabel(ylabel)
      plt.title(title)
      plt.show()