2. A certain production process produces two parts: a bearing and a shaft. In the final assembly the shaft and the bearing are randomly mating and a critical specification is the clearance between two parts. The distribution of the inside diameters of the bearing is normally distributed with a mean equal to 5.40 mm with a standard deviation of 0.735 mm. The distribution of the outside diameters of the shaft is normally distributed with a mean equal to 3.93 mm with a standard deviation of 0.413 mm. a. Estimate the mean and variance of the distribution of clearances for the bearing-shaft assemblies. b. Assuming that the mating of bearings and shafts is random estimate the proportion of assemblies that will not fit together. (Hint: The assemblies will not fit together if the clearance is less than or equal to zero.) c. By how much would the variances in clearances have to be reduced so that the proportion of defective assemblies is less than 1%?