Final answer:
The simple interest rate of 9.99% on $1 per year is 9.99 cents, and the total simple interest over 93 years is $9.29. Compound interest, on the other hand, can grow to a much larger sum, as demonstrated by the total amount of approximately $7,030.31 after 93 years.
Step-by-step explanation:
The simple interest rate of 9.99% on $1 per year is $0.0999, which can also be represented as approximately 9.99 cents. Simple interest is calculated using the formula Interest = Principal × Rate × Time, where the principal is $1, the rate is 9.99%, and time is expressed in years. When calculating the total interest over 93 years, without compounding, it would be $1 × 0.0999 × 93 = $9.29. Conversely, 9.99% compounded annually means that the interest is added to the principal amount at the end of each year before calculating the interest for the next year. After 93 years, the total amount using compound interest is approximately $7,030.31.