The inside diameter of a manufactured cylinder is believed to follow a normal distribution centered at 5.00 inches with standard deviation of .03 inches. The diameter of the cylinder must be within 4.95 inches (the lower specification limit) and 5.07 inches (the upper specification limit). If the diameter is outside these two specification limits, then the cylinder is nonconforming. What proportion of the manufactured cylinder are nonconforming?
STAT - PsyDAG, Tuesday, May 1, 2012 at 12:34pm
Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores. You are looking for the proportion in the smaller area.