Question: (a) Samples of size 50 are being drawn from a company's production line. It has been found that x¯ = 119, and σ = 0.7. If a 95% confidence level is wanted, estimate the population mean and determine the confidence interval.
(b) Suppose in (a), the sample size has not yet been determined, but n should be chosen to have a 99% confidence level and an error of no more than 0.2. Estimate the sample size that should be used.