A company has two factories, one in the UK and one in the Germany. There is a view that the German factory is more efficient than the British one, and to test this, a random sample is selected from each of the factories. The British sample consists of 20 workers who takes an average of 25 minutes to complete a standard task. Their standard deviation is five minutes. The German sample has 15 workers who take an average of 20 minutes to complete the same task, and the sample has a standard deviation of four minutes. Use an appropriate hypothesis test, at the 1% level of significance to find if the German workers are more efficient.