The same math test is given to a sample of elementary school students in Grades 1 through 4. The correlation between a students height and his or her score on the test is calculated to be r = 0.85....

Extracted text: The same math test is given to a sample of elementary school students in Grades 1 through 4. The correlation between a students height and his or her score on the test is calculated to be r = 0.85. This does not, however, indicate a causal relationship between the two variables. Which of the following is likely a lurking variable in this case? gender age teacher type of questions study time