Question

The piston rings are used to reject when a certain dimension is not within the specifications 2.0±d. It is known that this measurement is normally distributed with mean 1.50 mm and standard deviation 0.20 mm.

(4). Find the value d such that the specifications cover 90% of the measurements.

(5). What is the probability that the measurement of a selected piston ring will be more than 3 mm?

Answer 1

let = Dimensun Imeasurement of sing leject to is x is not within a id XN N (M21.5, o=0:2) ...P(2-d <XkQ+d) = 0.90 Pla-d-152x-u <Q+d-15) 20.90 o 0.2 P(0.5-d <Z < 0.5+ 1 = 0.9 from standard noormal tables P[-1.645 < Z41.645) = 0.90 0.2 0: 27 0,2 - d=-0,171 $ 24X73)= P( X73,)