Objective: This exercise illustrates how the confidence interval width depends on the sample size, the variability, and the level of confidence.
Problem Description: A machine produces cylinders that have normally distributed thicknesses with a mean of 8.1 cm and a standard deviation of 0.1 cm.
The Confidene Interval Applet below displays 90% confidence intervals on the true mean thickness computed for each of 100 batches each containing 5 cylinders. The cylinder thickness is normally distribution with µ = 8.1 cm and sigma = 0.1 cm.