Firms seek to maximize:

An omitted variable is a variable that:

A) is purposely left out as it does not aid an economic analysis. B) does not cause other variables in a study to change when it changes. C) is removed from a study as it can lead to the problem of reverse causality. D) has been left out, and if included, would explain why the variables considered in a study are correlated.

Refer to Table 1-3. What is Ivan's marginal benefit if he decides to stay open for six hours instead of five hours?

A) $10 B) $20 C) $30 D) $91.67