Quiz: Demonstration problem on text page 119
Since for parts A and B the situation is mathematically symmetrical, the number of defectives too narrow is the same as the number of defectives too wide
Using the results on text page 119, the percentage of defective parts that are too wide (or too narrow) is 0.38%
So for 10,000 parts, 38 are too narrow and 38 are too wide and the total number of defectives is 76