Assume a machine that has a useful life of only one year costs $2,000. Assume, also, that net of such operating costs as power, taxes, and so forth, the additional revenue from the output of this machine is expected to be $2,300. The expected rate of return on this machine is:

15%

Explanation:

Return on assets (ROA) is a financial ratio that shows how effective the investments in assets has affected the company's income. Mathematically, It is the ratio of net income to total assets where the Net income is the total sales less total expense.

Given that the assets fetches the company an additional income of $2,300 and the cost is $2,000

Net income = $2,300 - $2,000

= $300

Rate of return = $300/$2000

= 0.15

= 15%

ans.

heterothermic organisms include those organisms that can switch between homeothermic (having body temperature higher than environment) and poikilothermic (having variation in internal body temperature) strategies.

some migratory birds show heterothermy as they decrease their metabolic rate during cold nights to keep their body temperature low. drop in metabolic rate allows increase in production efficiency of birds that reduces the internal body temperature to make it equal to external cold temperature during cold nights.

thus, the correct answer is 'birds allow their temperature drop in order to increase their production efficiency.'