A particular manufacturing design requires a shaft with a diameter between 19.92 mm and 20.015 mm. The manufacturing process yields shafts with diameters normally distributed, with a mean of 20.002 mm and a standard deviation of .006 mm.

a. For this process what is the proportion of shafts with a diameter between 19.92 mm and 20.00 mm?

b. For this process what is the probability that a shaft is acceptable?

c. For this process, what is the diameter that will be exceeded by only 1% of the shafts?