Answer:
I earned an annual rate of return of 34.9%.
Explanation:
A = P(1 + r)^n
A is the amount the antique was auctioned = $8000
P is the amount the antique was bought = $400
r is the annual rate of return
n is the duration of the investment = 10 years
$8000 = $400(1 + r) ^10
(1 + r)^10 = $8000/$400
(1 + r)^10 = 20
1 + r = 20^0.1
1 + r = 1.349
r = 1.349 - 1
r = 0.349 × 100 = 34.9%
