7.86 Defective Light bulbs The table lists the number of defective 60-watt light bulbs found in samples
Question:
7.86 Defective Light bulbs The table lists the number of defective 60-watt light bulbs found in samples of 100 bulbs selected over 25 days from a manufacturing process. Assume that during these 25 days the manufacturing process was not pro- ducing an excessively large fraction of defectives.
a. Construct a p chart to monitor the manufacturing process, and plot the data.
b. How large must the fraction of defective items be in a sample selected from the manufacturing process before the process is assumed to be out of control?
c. During a given day, suppose a sample of 100 items is selected from the manufacturing process and 15 defective bulbs are found. If a decision is made to shut down the manufacturing process in an attempt to locate the source of the implied control- lable variation, explain how this decision might lead to erroneous conclusions.
Step by Step Answer:
Introduction To Probability And Statistics
ISBN: 9780176509804
3rd Edition
Authors: William Mendenhall