A certain adjustment to the machine will change length of the parts it makes but will not affect the standard deviation. The length of the parts is normally distributed, and standard deviation is 0.5 mm. After an adjustment is made, a random sample is taken to determine the mean length of parts now being produced. The resulting lengths are as follows.
75.9 76.8 75.7 77.6 76.3 76.9 77.6 75.5 77.0 77.2
Find the 0.99 confidence interval for ?(mu). (Give your answer correct to three decimal places.)