The One Variance command analyzes a sample from a population, and calculates confidence intervals for the standard deviation and variance of that population. It also features an optional hypothesis test to determine whether the unknown population standard deviation or variance is equal to a user-specified value. This test is useful to determine whether your variance is different from an industry standard, for example.

The manager of a lumber yard wants to analyze the performance of the saw mills. One mill is designed to produce beams that are exactly 100 cm long. The manager decides to analyze the variance of these lengths to better understand the precision of the equipment. The manager takes a sample of 50 beams, measures their length in centimeters, and analyzes the variance of this single population using the 1 Variance Test.

Data: SawMill.MTW (available in the Sample Data folder).