a packing device is set to fill detergent powder packet with a mean weight of 5 kg . The standard deviation is known to be 0.01 kg. these are known to drift upwards over a period of time due to machine fault, which is not tolerable. A random sample of 100 packets is taken and weighed. This sample has a mean weight of 5.03 kg and a standard deviation of 0.21 kg. can you conclude that the mean weight produced by the machine has increased? use a 5% level of significant?