Julie eats lunch at the cafeteria on campus daily, Monday through Friday. Her lunch costs $5.25. How much money could she save in four weeks if she starts bringing her lunch from home?
There are 5 days in a week, so Julie eats lunch at the cafeteria 5 days a week.
In a week, Julie spends 5 * $5.25 = $<<5*5.25=26.25>>26.25 on lunch.
In four weeks, Julie spends 4 * $26.25 = $<<4*26.25=105>>105.
If Julie starts bringing her lunch from home, she could save $105 in four weeks. Answer: \boxed{105}.