The Northeastern United States is getting another snowstorm! Sean, a fifth grade student, decides he will measure how many inches of snow he gets outside his apartment building. Before he goes to bed, he measures and records the snow as 4 and 3/4 inches high. When he wakes up in the morning (snow day!), he measures again and records it as 12 and 1/8 inches high. How much snow fell overnight outside Sean's apartment?