You can even clear it with a down-filled bag. Lafuma's Warm'N Lite 600 Down has down fill, a temperature rating of 40 degrees, a weight of only one pound, three ounces, and the low, low price of $99 (www.lafumausa.com). For just $70 more you can get the Katahdin 20 from L.L. Bean, a pretty serious bag with a 20-degree rating, good-quality 650-fill down, and full draft collars at the neck and along the zipper (www.llbean.com). Or, Mammut's Island Summer has a 40-degree rating, 650-fill down, and very reasonable $145 price tag (www.mammut.ch).
There are also plenty good choices in synthetic bags, too. REI's Nooksack UL 35 ($159; www.rei.com) uses Primaloft insulation, which is my favorite synthetic, plus a durable shell of high-quality Pertex nylon. It weighs just over two pounds, compresses to nothing, and keeps you comfortable to just above freezing. Slumberjack also makes a line of decent, budget-priced bags, such as their Super Guide, rated to 30 degrees and costing only $69 (www.slumberjack.com). It would work just fine for you.
So there you go. Lots of bags for not much dough. You'll do well in your accounting classes if you purchase any of these.