For the following four questions, use the appropriate formula and your t-Test table in Appendix B2. Use the following study set-up:
A researcher is interested in seeing if negative political ads against an opponent (group one) are more persuasive than positive ads for an original candidate (group two). She creates a scale to measure how persuasive the ads are; larger numbers mean more persuasive.
She collects the following data (put these numbers down; they don't appear on the followup questions):
Group One (Negative ads): x¯1= 7.3, s12= 2.64, n1 = 20
Group Two (Positive ads): x¯2= 9.36, s22= 4.8, n2 = 20