Answer:
$40.5
Step-by-step explanation:
Interest is calculated using the formula.
I= p x r x t
where I = interest
p= principal amount: $1200
r= interest rate: 4.5% or 0.045
t= time in year. 9 months which is 9/12 or 0.75 years
i =$1200 x 0.045 x 0.75
I =$54 x 0.75
I =$40.5
Interest earned is $40.5