In order to calculate the volume of the rectangular prism, use the following formula:
V = b·h
where
b: base of the prims = 2 1/2 in²
h: height = 11 1/2 in
write the mixed numbers as fractions:
b= 2 1/2= (4 + 1)/2 = 5/2 in²
h = 11 1/2 = (22 + 1)/2 = 23/2 in
next, replace the previous fraction into the formula for V:
V = (5/2 in²)(23/2 in)
V = 115/4 in³
finally, write the previous result as a mixed number:
115/2 in³ = 28 3/4 in³
Hence, the volume of the rectangular prism is 28 3/4 in³