we know that
[scale]=measure model airplane/measure actual airplane
scale=1/78
measure actual airplane=measure model airplane/scale
measure actual airplane=15/(1/78)----> 15*78-----> 1170 in
1 ft------------> 12 in
X---------> 1170 in
x=1170/12-----> 97.5 ft-------> 98 ft
the answer is
98 ft
