Answer:
1 : 18
Explanation:
When finding scale factor, both measurements should in same unit
Circumference of the model bell = 8 inches
1 feet = 12 inches
12 feet = 12 * 12 = 144 inches
Circumference of the actual bell = 12feet = 144 inches
Model : Actual = 8 : 144
= 8÷8 : 144÷8
= 1 : 18