input: 
  from sklearn.linear_model import LinearRegression
  import numpy as np
  
  def perform_linear_regression(X, Y):
      """
      Perform linear regression on the given dataset to predict the output Y based on input X.
      >>> perform_linear_regression([1,2,3,4,5], [3,5,7,9,13])
      [15.]
      """
      X = np.array(X).reshape(-1, 1)
      Y = np.array(Y)
      
      model = LinearRegression()
      model.fit(X, Y)
      
      return model.predict([[7]])
  
output:     X = np.array(X).reshape(-1, 1)
      Y = np.array(Y)
      
      model = LinearRegression()
      model.fit(X, Y)
      
      return model.predict([[7]])