Answer: 
2.75feet 
Step-by-step explanation: 
Given data 
Volume= 11.39 cubic feet 
Length= 2.3 feet 
Width= 1.8 feet 
Depth= ??? 
The expression for the volume is 
Volume= Length*Width*depth 
11.39=2.3*1.8*d 
11.39=4.14d 
d= 11.39/4.14 
d= 2.75 
Hence the depth is 2.75feet