There is a shortage of every good that is scarce

If an increase in disposable income causes consumption to increase from $4,000 to $10,000 and causes saving to increase from $2,000 to $4,000, it can be inferred that the MPC equals

A. 0.5. B. 0.75. C. 0.4. D. 0.6.

A concentration ratio gives

A. the sales of the four largest firms in the industry divided by the sales of the eight largest firms in the industry. B. the percentage of all sales contributed by the four or eight largest firms in the industry. C. the total sales of four or eight of the mid-sized firms in the industry. D. the average size of the firms in an industry.