input: Write a function to implement the exponential smoothing algorithm to predict the next day's forecast temperature given the past three day's forecast temperatures. The function should return the predicted temperature.
  
  def predict_temperature(temperature_list):
      alpha = 0.5 # Confidence value
      predicted_temperature = temperature_list[-1] # Initializing prediction
      for temperature in temperature_list[:-1]:
          predicted_temperature = alpha*temperature + (1-alpha)*predicted_temperature
      return predicted_temperature
  
  assert predict_temperature([21, 22, 20])==21.0
  assert predict_temperature([25, 24, 26])==25.0
  assert predict_temperature([18, 19, 20])==19.0
  assert predict_temperature([30, 28, 29])==29.0
  assert predict_temperature([15, 14, 16])==15.0
output: def predict_temperature(temperature_list):
      alpha = 0.5
      predicted_temperature = temperature_list[-1]
      for temperature in temperature_list[:-1]:
          predicted_temperature = alpha * temperature + (1 - alpha) * predicted_temperature
      return predicted_temperature