The expression 1,000 (1.0215) 4t represents the amount of money in an account after t years. The interest is compounded, and the effective annual interest rate on the account is.

Rate = r = 8.6 %

Step-by-step explanation:

For compound interest

A = P (1 + r/n) ⁴t = 1000 (1.0215) ⁴

from above we have 1.0215 = 1 + 0.0215 = 1+r/4

0.0215=r/4

r = 0.0215 * 4=0.086 = 8.6 %

where A is the amount

P = Principal

interest Rate = r

n = number of times interest is applied per year

t = number of years (time)

for t = 1

A = 1000 (1.0215) ⁴ = 1000 (1.0888) = $ 1088.813

for t = 2

A = 1000 (1.0215) ⁸ = 1000 (1.18554) = $1,185.515