Theresa invested $5,000 in an account she expects will earn 20% annually. Approximately. how many years will it take for the account to double in value? (Report an integer) (Hint: The easiest way to solve this problem is to use the "rule of 72".) (Note: Approximately, 1.3 is 1 , not 2 ; and 1.5 is approximately 2. )