27. A manufacturing process is designed to produce ball bearings with a diameter of 0.620 cm. The standard deviation of all ball bearing diameters is 0.009 cm. Every day a random sample of 40 ball bearings is selected and their diameters are measured. If the mean diameter from this sample falls outside of a given range, then the management will stop production to make adjustments. For the range 0.619 cm to 0.621 cm, find the probability that the management will stop production unnecessarily. (Hint: Find the probability that a sample's mean will have a value inside this range when the population mean actually is 0.620 cm, and then use complements to find the probability that a sample mean's value is outside that range.)