Dr. Ramon found a negative correlation between the amount of television children watch in the home and their achievement in school as measured by their grades. He found that the more television children watched the lower their grades. But further research indicated that many of the children have more time at home unsupervised and the lack of supervision is also related to poor grades. The lack of home supervision is a(n) problem.

The lack of home supervision is a THIRD VARIABLE PROBLEM.

Explanation: A third variable problem is defined as an extraneous variable in a statistical model in which a third variable leads to an erroneous irregular relationship between two others.

The first two relationship is between the more television children watched the lower their grades. The third variable here is the lack of supervision.

by using  production possibilities graph.  opportunity costs are key expenses in financial matters and are utilized as a part of registering money saving advantage investigation of a venture. such expenses, be that as it may, are not recorded in the record books but rather are perceived in basic leadership by processing the money costs and their subsequent benefit or misfortune.