Question: A mixing tank after a process can, in some cases, reduce the effect of process variability prior to providing the product to the customer. Discuss the effects of product mixing on the following processes. Specifically, would the mixing reduce the variability important to the customer when the mean of the production is correct but the variance of the material entering the tank is too large?

(a) The bottoms product of a benzene-toluene distillation tower is mixed in a tank. The customer is interested in the percent benzene impurity.

(b) The ball bearings from a manufacturing plant are mixed in a bin. The customer is interested in the diameter of each ball bearing.