A researcher conducts a survey examining eating and sleeping behavior as well as academic performance for a group of elementary school children. The results of the survey indicate that the children who eat a more nutritious breakfast tend to have better grades than the children who have a breakfast low in nutrition. However, the research suspects that the children's parents may be responsible for this relationship. Specifically, the better-educated parents probably encourage their children to eat better food and work harder in school compared to parents with less education. If the researcher is correct, this is an example of the . third-variable problem directionality problem reversal problem criterion problem

third-variable problem

Explanation:

Third variable problem refers to the common correlation that exists between two correlated variables. According to third variable problem, there exists a third variable that can be the reason of a correlation being existing between the two variables. In the given expert, the third variable is the education of the parents of the children that exists between the other two variables. The first two variables were the academic performance of the children and their level of nutrition. With the help of the third variable the argument was presented that education level of the parents had a correlation between the academic performance of the children and their level of nutrition.

why does vagina taste like fish water (asking for a friend)

the factors that the economies of the muslim empires prosper were:

1- land trade routes-located between three continents  

2- sea trade routes

trade contributed to the spread of muslim empires, and with that islamic culture led to a growing feeling of internationalism resulted in the transfer of technology, science, and other cultural forms.