The packaging lists a model airplane’s length as 15 in. it also gives the scale as 1: 78. what is the length of the actual airplane to the nearest foot?

For this case we have the following relationship:
 15 / x = 1/78
 Clearing the value of x in this case we have:
 x = (15) * (78)
 x = 1170 inches
 
 The length of the current airplane to the nearest foot is:
 x = 1170 inches

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