In: Math
In the manufacturing process of carbon composition resistors historical records indicate that 80% of these components have superior quality, 10% have very good quality, 5% have marginal quality and 5% are poor (non-shippable). A quality control firm implemented changes to the manufacturing plant (like installing dehumidifiers) and several months later a random sample of 1200 carbon composition resistors we gathered and rated. Here’s what was found:
Superior:996 Very good:126 Marginal:48 Poor:30 Total:1200
Answer the following questions below.
(a) Test if there is evidence to suggest that the implemented
change changed the distribution. Use α = .05.
(b) Looking at each of the (Xi−Ei)2 , which is the largest and construct a 95% confidence interval the multi- Ei
nomial proportion corresponding this ratio.
(c) Would you believe that the installation of dehumidifiers
improved the quality? Briefly explain.