tiffani lind got her new weekly course schedule from roxbury community college in boston. following are her classes and their length: business math, 2 1/2 hours; introduction to business, 1 1/2 hours; microeconomics, 1 1/2 hours; spanish 2 1/4 hours; marketing, 1 1/4 hours; and business statistics, 1 3/4 hours. how long will she be in class each week