Answer:
1 : 4 . . . . or . . . . 1/4
Explanation:
... 15 in : 5 ft . . . . . . given
... 3 in : 1 ft . . . . . . . divide by 5
... 3 in : 12 in . . . . . express using the same units
... 1 : 4 . . . . . . . . . . . divide by 3 in
This can also be written as 1/4.