Answer:
10%
Step-by-step explanation:
The appropriate formula for the future value of an account with compound interest is ...
A = P(1 +r)^t
where r is the annual rate, and t is the number of years.
Fill in the given values and solve for r:
4840 = 4000(1 +r)^2
4840/4000 = (1 +r)^2
√1.21 = 1 +r
1.1 = 1 +r
r = 1.1 -1 = 0.10
r = 10%
The rate is 10%.
