Question: Again, as part of the manufacturing process for its personal computers, Empire Electronics electroplates various precious metals onto certain circuitry. All of the parameters for the platinum plating for a new circuit, Model Gamma, have not yet been established. However, preliminary research yielded an estimated population standard deviation of 3.24 micro-inches. How large a sample is necessary to estimate the true population mean thickness for effective and efficient platinum plating with 95% confidence, presuming the acceptable error bound is 0.5 micro-inches? [COMMENTS & HINTS: Round off the answer appropriately.]