The Central Limit Theorem: states that the average range can be used as a proxy for the standard deviation. states that the average of assignable variations is zero. controls the steepness of an operating characteristic curve. is the theoretical foundation of the c-chart. allows managers to use the normal distribution as the basis for building some control charts.

The correct answer is - allows managers to use the normal distribution as the basis for building some control charts.

Explanation:

It is the theorem that allows inference from a random sample. It says that:

•The sample mean will likely be towards the population mean within a margin of error

•The margin of error is a multiple of the standard error, which is the standard deviation divided by the square root of the sample size. The multiple is determined by the degree of statistical confidence you’re looking for, and the normal deviate corresponding to that — 1.65 for 90% confidence, 1.96 for 95% confidence, etc.