Answer:
[tex]\sigma=0.000215\\[/tex]
Step-by-step explanation:
[tex]\mu=0.002 inches\\P(0.0014<x<0.0026)=0.9973\\[/tex]
[tex]z=\frac{x-\mu}{\sigma}[/tex]
[tex]\sigma = \frac{x-\mu}{z}[/tex]
We obtain z from the normal distribution tables:
As P (0.0014<x<0.0026)=0.9973), we search 0.9973 on the table, to obtain
z= 2.78
[tex]\sigma = \frac{0.0026-0.002}{2.78}=\frac{0.0006}{2.78}= 0.000215[/tex]
