Final answer:
The statement is false as an optimal mix-model production schedule must consider the production possibilities curve and opportunity costs beyond just the proportion of products in the mix.
Step-by-step explanation:
The statement is false. An optimal mix-model production schedule takes into account the product mix as well as considerations of scheduling, capacity, and the opportunity cost associated with producing different products. Given that a firm's product mix is 60 per cent of product A and 20 per cent each of products B and C, a sequence of production such as AAABC may not necessarily represent an optimal schedule. Factors such as the combined production possibilities curve and opportunity costs must be taken into account.
For instance, if 'A' represents skis and 'B' and 'C' represent different types of snowboards, and if snowboards at Plant 3 have a lower opportunity cost than skis, it might be optimal to shift this plant to produce more snowboards rather than skis, as indicated when Alpine Sports moves from point A to point B, producing 100 snowboards leading to a reduction of 50 pairs of skis.