Thermo: Change in temp effect on volume of a steel container

[PhysLiz]

Homework Statement

The average coefficient of volume expansion for carbon tetrachloride is 5.81*10-4 (°C)-1. If a 49.0 gal steel container is filled completely with carbon tetrachloride when the temperature is 10.0°C, how much will spill over when the temperature rises to 27.0°C?

Homework Equations

ΔL = α*(original length)*ΔT

The Attempt at a Solution

I used this equation except instead of units of length, I substituted units of volume. So my final equation was:
ΔL = (5.81E-4 (°C)-1) * (49.0 gal) * (27°C - 10°C) = 0.484 gallons. This is incorrect, but within 10% of the correct answer. Not sure what I am doing wrong. Any help is greatly appreciated, Thank you!

 

[PhysLiz]

I have solved it - thanks anyway!