Donald thinks that goal of six-sigma is arbitrarily high. After having studies business optimisation skills under ETF5650, you are not surprised at all. Can you help Donald understand that even delivery of very high-quality products can lead to the need for six-sigma standard?

Let me help you here by suggesting an empirical situation.

A popular family restaurant in Caulfield offer high quality food products. The restaurant boasts of 98% quality in their products. This is actually true. A typical single meal at the restaurant comprise of 5 food products. You may safely assume that all product quality is independent of each other. You should be able to help Donald alleviate his fears by considering the probability of occurrence of the following three cases.

A single meal is of high quality

A family of 4 eats at the restaurant and all four meals are of high quality

A family of 4 eats at the restaurant once every month in a year and during all 12 visits the family finds all meals are of high quality