In rational expectations theory, the term "optimal forecast" is essentially synonymous with

The figure above shows a production possibilities frontier. In the figure, which of the following combinations of the two goods are efficient?

A) 4 million cell phones and 4 million DVDs B) 2 million cell phones and 13 million DVDs C) 5 million cell phones and 15 million DVDs D) no cell phones and 15 million DVDs E) None of these combinations is efficient.

A quintile is 20% (one-fifth) of a population group

Indicate whether the statement is true or false