Simple beam calculation

Uniform load of a total of 50 lbs even distribution on a 12 foot span with fixed supports.

Square steel tube
1.5 inches square
14 gauge steel (wall thickness of .078")
E = 30000000 psi
I = 0.1502
W = 50lb
L = 12 ft

My deflection calculation differs from "Beam Boy" software and I can't find the error. I get
0.0863 inches of deflection.

I used this formula:

WL^3/384EI