For this case we have an equation of the form:
y = A * (b) ^ t
Where,
A: initial cost
b: growth rate
t: time in years
Substituting values we have:
y = 7500 * (1.1275) ^ t
For year 6 we have:
y = 7500 * (1.1275) ^ 6
y = 15408.50724
Answer:
y = 7500 * (1.1275) ^ t
y = 15408.50724 $ (year 6)