describe the general changes in economic systems from the ancient greek and roman systems to the beginning of modern economic thought

answer:

d. because dr. laguardia selected a widely used measure, his study generalizes to has strong external validity. external validity has limited external validity. other applications of this measure.

the widely used measure that he applied to his experiment was the benton facial recognition test. it employed on to football players and as result, only players who suffered brain concussions did not pas this test. and although it has an external validity, it is limited because it isn't general to apply to other population.

an important point to remember about correlation is that while there is a _statistical_ relationship correlation does not equal _causation_

the first answer is: statistical

the second answer is: causation

answer; compulsions is a term that refers to repetitive behaviors performed;