Whenever a firm's marginal costs are less than its average costs, its average costs must be:

The marginal cost to a student of missing a class meeting in Introductory Economics increases when

A) textbook prices increase. B) tuition rates increase. C) valuable information is communicated in the class meetings. D) any of the above occurs.

If grades are to be a successful signal to potential employers of a student's qualities, then higher grades must be

A) easier for high-productivity students to earn than for low-productivity students to earn. B) easier for low-productivity students to earn than for high-productivity students to earn. C) easy for employers to check. D) used for all future promotions within the firm. E) often referred to in the hiring process.