Refer to the table shown. If the number of workers is three, total output is:Number of workersMarginal product of workers1225394145166177188189171015 

Factory workers who work the day shift earn less per hour than similarly-skilled factory workers who work the night shift. The difference in pay is attributed to

a. the marginal product of labor. b. the marginal product of capital. c. diminishing marginal returns. d. a compensating differential.

The long run significance of investment is due to

a) its volatility b) the importance of capital to economic growth c) the effect of income on investment d) the procyclical nature of investment e) its ability to crowd-out government expenditures