Answer:
Stage crewmember's calculation is incorrect
Correct = 1/16x 1/16y
Explanation:
Given that:
Dimension of backdrop : 20 feets long ; 16 feets high
Actual dimension of building : 320 feets long ; 256 feets high
The correct scale factor can be obtained thus :
Ratio of backdrop dimension to the actual dimension of building
Length : 20 / 320 = 1 /16
Height : 16 / 256 = 1/16
Hence, stage crewmember's calculation of (1/20x ; 1/20y) is incorrect.