Answer:
The bell is 4.5 feet tall
Step-by-step explanation:
The ratio of the replicas are 1in : 0.5ft, so each inch of the model is 0.5 feet in real life.
The replicas are 9 inches tall, so you would multiply by the scale factor, 0.5 feet. You want the units to end up being feet, so you position the fractions to cancel out inches.
in x

the inches cancel out and you are left with:
9 x 0.5 ft
Simplify.
4.5 ft