A sample distribution closely approximating a normal distrib
A sample distribution (closely approximating a normal distribution) of a critical part dimension has an average of 11.85 inches and a sample standard deviation of 1.33 inches. The lower specification limit is 11.41 inches. The upper specification limit is 12.83 inches. What percentage of parts will be produced below the lower specification limit of 11.41 inches?
Solution
P(X<11.41) = P(Z<0.44/1.33)=P(Z< 0.0300) =0.5120
51.40% will be below 11.41.

