Which of the following is true of moderators? a. They weaken statistical significance. b. They can inform external validity. c. They help establish a cause and effect relationship. d. They decrease effect size.

c. They help establish a cause and effect relationship

Explanation:

every society, in order to meet the needs of it's people, has to answer three basic questions:

- what should we produce?

- how should we produce it?

- for whom should we produce it?

this questions must be answered in order to, option b, aid in production decisions.

every country can't produce everything, no matter how rich their land is. it may be a matter of technology, resources or geographical conditions. so, these three questions must be resolved in order to get the most of the production of each land.

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