2-5. A fluid is pressurized
by a piston to a normally distributed pressure 
psi as
shown in the following two ways. The piston has a diameter of 
. The allowable stress of the container
wall also follows a normal distribution 
psi.
Determine the minimum thickness 
for both cases if the
maximum probability of failure is 10-4. Assume 
and 
are
independent. (Ans. 
)
