Brian researched how a person's intelligence quotient (IQ) is affected by exercise. First, people took an IQ test. Then, over 2 months, they did different amounts of exercise. Then, Brian gave them a second IQ test. What is the response variable in this experiment

The question is incomplete and the full version can be found online.  

The change in IQ score from the first to second test

Explanation:

In an experiment, the response variable is the purpose of the question that is being made, while the explanatory variable is the one that has an effect over the response variable, meaning that it explains any changes in it.

If Brian is examining the effect that exercise might have on a person's intelligence quotient (IQ), the question he´s making is: does exercising change IQ results? Therefore, the change in IQ is the response variable. The amount of exercise is the explanatory variable, and the experiment aims to determine whether or not it has an effect on the response variable.

Incorrect options: The number of people in the study is the sample under study, not the response variable. The first IQ test score would be one indicator of the variable, not the variable itself. And the amount of exercise the people do is the explanatory variable, not the response variable.

c is the answer for this

levels of production can be increased by technology while holding labor and capital constant, because increased technology makes the production process more efficient. subsequently, the lras curve is almost a vertical line, that can shift to the right, with an increase in technology.

the relationship between the lras curve and the ppc is that both can make the economy could grow. the ppc achieves that when it shifts outward because of more resources or technological advances while the lras curve shifts if more resources are developed or if there are technological advances.

the lras curve is a vertical line at an output level that represents the number of goods and services a nation can produce over a sustained period using all of its productive resources as efficiently as possible with all of the current technology available to it.

the production possibilities frontier (ppf) is a graphical device that is used for economic analysis of production decisions because the ppf measures the maximum possible combinations of two goods that an economy is capable of producing with its currently available resources and technology.