Apsychologist is interested in looking at the effectiveness of a new computer program in students learn math. she decides to test this new program with a group of middle school students. at this particular school, the boys and girls tend to be disruptive when they are in the same classroom, so she decides to run them separately in the experiment. she creates a group of boys who use the computer program four times per week. she creates a group of girls who do not use the computer program to serve as a comparison group. this experimental design is flawed because gender is a and as a result, the internal validity of the study has been

confounding variable; lowered.

Explanation:

In the field of statistical analysis, a confounding variable is one that influences both the independent variable and the dependent variable. When an experimented is designed, the researcher wants to study the effect the independent variable has on the dependent variable. However, if there's a third variable that can influence them, it can cause a spurious correlation.

The psychologist wanted to test the effects using the new computer program (independent variable) had in helping students learn math (dependent variable). But when she divided the group in two, separating them by gender, she introduced a third variable (confounding variable) that wasn't accounted for when designing the experiment and that can influence either variable. Because of this, the internal validity of the study has been lowered.

even though you have attached neither the chart nor the generalizations, i have located them online. the right answer is d, since they are asking you about a generalization. you can only infer from the chart that between 2008 and 2009 the number of employed workers decreased significantly (from over 115 millions to 107 millions approximately), which signals some type of economic crisis.