A major university would like to improve its tarnished image following a large on$-$campus scandal. Its marketing department develops a short television commercial and tests it on a sample of n $=10,$ the first ten students who entered a housing commons area who agreed to participate. Attitudes about the university are measured with a short questionnaire, both before and after viewing the commercial. Attitudes were on a scale of $020,$ which higher numbers reflecting better attitudes. Use the provided data to examine whether the commercial improved the university$$s image. The data are as follows: $1.$ In this specific scenario, what is the independent variable? Is it between or within subjects? How many levels does it have, and what are they?