Refer to the given data. In maximizing its profit, this firm will employ:

To see how variables evolve over time we use

A) a scatter graph. B) an evolution plot. C) a cross-section plot. D) a time-series graph.

Why don't we see firms tie-in the sales of fish filets with the sales of pencils?

A) because the demands for these two goods are positively correlated B) because the demands for these two goods are negatively correlated C) because the demands for these two goods are independent D) It violates the Clean Food Act of 1908.