The claim made by a cell-phone battery producer company is that the life-length of the battery it fabricates has a distribution with a mean of 108 months and with a standard deviation of 9 months....

Extracted text: The claim made by a cell-phone battery producer company is that the life-length of the battery it fabricates has a distribution with a mean of 108 months and with a standard deviation of 9 months. However, this producer was returned with lots of complaints from the cell-phone manufacturers that had incorporated this new battery into their products, so that they argued that the life-length of the battery is shorter than the claimed duration, indeed. They took an action and report their claims to a state agency. Now, the state agency wants to explore the claims made by these cell-phone manufacturers by drawing 60 number of batteries randomly. b) assuming that the cell-phone battery producer company is right in its claim please calculate and interpret the probability that the selected sample has a mean life which is between 55 and 65.