Newton currently has an account balance of $6225.18. He opened the account 15 years ago with a deposit of $4543.11. If the interest compounds daily, what is the interest rate on the account?

Formula of the daily compound interest:

A = P. e^ (r. t), where P is the initial investment, r = interest rate, t = number of years e = 2.718 and A = final amount

6,225.18 = 4,543.11 (e) ^ (r. 15)

(e) ^ (r. 15) = 6,225.18/4,543.11

(e) ^ (r. 15) = 1.3702046

ln[ (e) ^ (r. 15) ] = ln (1.3702046)

15. r = 0.314991

And r = 0.314491/15 = 0.020 OR 2%