Answer:
Petroleum was used as fuel as early as the fourth century BC.
Explanation:
Answer:
protective colorings that make. an organism to be part of its surrounding is camouflage
Answer:
Confounding variable
Explanation:
The confounding variable is the variable that is extra in variables. It is not counted by the experimenter in the research experiment. With the help of confounding variables, it can be explained that it is cor-relational but in actual it is not there. This variable introduces the bias ness in the experiment.
confounding variable is the variable that affects the variable hidden on its outcome. But technically if we see confounding is not a true bias. Bias occurs when there is an occurrence of an error in data collection. In confounding variable there is positive bias occur when an association of bias is away from null and negative bias occur when it is associated with null.
Hello. This question is incomplete. The full question is:
"Technological improvements and reduced equipment costs have made converting solar energy directly into electricity far more cost-efficient in the last decade. However, the threshold of economic viability for solar power (that is, the price per barrel to which oil would have to rise in order for new solar power plants to be more economical than new oil-fired power plants) is unchanged at thirty-five dollars. Which of the following, if true, does most to help explain why the increased cost-efficiency of solar power has not decreased its threshold of economic viability?
(A) The cost of oil has fallen dramatically. (B) The reduction in the cost of solar-power equipment has occurred despite increased raw material costs for that equipment. (C) Technological changes have increased the efficiency of oil-fired power plants. (D) Most electricity is generated by coal-fired or nuclear, rather than oil-fired, power plants. (E) When the price of oil increases, reserves of oil not previously worth exploiting become economically viable."
Answer:
(C) Technological changes have increased the efficiency of oil-fired power plants.
Explanation:
Economic viability is able to reveal the degree of acceptance of consumers in relation to a specific product. This viability is important to understand how the product will be received in the market and how profitable or not it can be for those who produce it.
Economic viability is usually greater when the cost and benefit ratio of the product or service is favorable, however this is not always the case.
Regarding the use of solar energy, although technological changes have made the installation and equipment of this type of energy more cost-effective, these technological changes have also increased the efficiency of oil plants. As a result, the economic viability of solar energy has declined.
