Follow the 7 steps of Hypothesis Testing.

In the area of Technology, professionals have developed a new artificial chip constructed using titanium and plastics. Once implanted, the artificial chip will last and operate almost indefinitely but the battery needs to be recharged about every four hours. A random sample of 40 battery packs is selected and subjected to a life test. The average life of these batteries is 4.09 hours. Assume that battery life is normally distributed with a standard deviation of 0.32 hours Using 95% confidence level, test if the mean battery life is more than 4 hours.