The diameter of steel shafts produced by a certain manufacturing process should have a mean diameter of 0.225 inches. The diameter is known to have a standard deviation of 0.0001 inches. A random sample of 10 shafts has an average diameter of 0.2545 inches.
a) Construct a 99% confidence interval of the true mean
b) Determine the minimum error
c) How large a sample is required if we want to be 99% confident that our estimate of "μ" is off by less than 0.05? Is the sample size in part a) adequate?