A manufacturing process produces discs for computer disk drives, which have an average thickness of 2.5 mm. Once a day a random sample of 100 discs is taken and the thickness of each is measured. If the sample mean is less than 2.39 mm or greater than 2.61 mm, the process is shut down and inspected. Assume that the process produces discs with the standard deviation of the thickness being 0.45 mm. On a given day, what is the approximate probability that the process will be shut down