Question: Researchers asked a sample of 50 1st grade teachers and a sample of 50 12th grade teachers how much of their own money they spent on school supplies in the previous school year. They wanted to see if teachers at one grade level spend more than teachers at the other grade level.
a. What type of study is found-observational or randomized experiment? Explain.
b. What is the experimental (or observational) unit?
c. What is the response variable?
d. What is the explanatory variable?
e. Do we have to worry about confounding variables in this instance? Why? If so identify a possible confounding variable?
f. Are either of the terms retrospective study or prospective study relevant? Explain.