A particular manufacturing design requires a shaft with a diameter of 18.000 mm, but shafts with diameters between 17.989 mm and 18.011 mm are acceptable. The manufacturing process yields shafts with diameters normally distributed, with a mean of 18.005 mm and a standard deviation of 0.006 mm. Complete parts (a) through (d) below a. For this process, what is the proportion of shafts with a diameter between 17.989 mm and 18.000 mm? The proportion of shalts with diameter between 17 989 mm and 18.000 mm is . Round to four decimal places as needed)