In order to determine the effectiveness of a new vaccine that is alleged to cure "math anxiety," a study was conducted. One thousand volunteer college students enrolled in math courses across the U.S. were chosen. The 1000 students were broken up into two groups. Those enrolled in calculus courses were given the real vaccine. The students in developmental (remedial) math courses were given a fake vaccine consisting of sugared water. None of the students knew whether they were being given the real or the fake vaccine, but the researcher conducting the study knew. At the end of the semester the students were given a test that measured their level of math anxiety. The students in the treatment group showed significantly lower levels of math anxiety than those in the control group. On the

Question

basis of this experiment the vaccine was advertised as being highly effective in fighting math anxiety.Which of the following is the most likely confounding variable for the study?

A. the students' background in mathematics
B. the students' grade level (freshman, sophomore, junior, senior)
C. the student's sex (male, female)
D. the type of college attended (two year, four year, public, private university)
E. none of these

Answer 1

Answer: A