by StaceyKoprince Fri May 15, 2009 2:40 pm
Yep, typo. The question asks for S-sub-4 - S-sub-2 and S-sub-2 = 45, not 15 (15 = S-sub-1). I'll forward to our curriculum director in case it hasn't been spotted yet. Thanks!
Stacey Koprince
Instructor
Director, Content & Curriculum
ManhattanPrep