British investigators conducted a study to compare measles-mumps-rubella (mmr) vaccine history among 1,294 children with pervasive development disorder (e. g., autism and asperger’s syndrome) and 4,469 children without such disorders. (they found no association.) this is an example of which type(s) of study?

Retrospective cohort study

Explanation:

Retrospective cohort studies are known as or referred to as the type or kind of observational research under which investigators tend to look back at historical data that is archived in order to examine if risk of the disease was different in between the patients who were exposed and non-exposed. Observational epidemiological designs  under which the risk of the disease is retrospectively compared in between the patients which are exposed and non-exposed.

answer; ///(c) i believe that the correct answer is ethnic relations bear many similarities across different global; good luck

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.