Basically, the marginal principle helps us to evaluate the factors involved in taking an action or if doing something is worth the effort

The historical record for the United States over the last 100 years shows

A) mostly positive economic growth, though the Great Depression caused actual GDP to dip well below potential GDP. B) economic growth for about half the years and economic decline for the other half. C) growth until 1970 and then a period of constant per person real GDP. D) continuous economic growth for each year, although at different rates, throughout the entire century.

Launching the complicated version would be a mistake for probabilities less than ___?

a. 0.2 b. 0.28 c. 0.30 d. 0.32