An author just signed a lucrative contract with a publisher that offers to pay her the amount of $500 at the end of year 7 when the book is scheduled to be released. The author, being profligate, desires to receive a different package: an immediate payment of $100 that is followed by an annuity (an equal amount) to be paid at the end of each year for 7 consecutive years. What annuity will make his package equivalent to the publisher's advance. Use an interest rate is 7.00%.