economics question

"A company is considering entering into a new marketing campaign. If it engages in this marketing campaign, it must pay $9,000 immediately and $7,000 each at the end of year 1 and year 2. The company believes its annual revenues due to the marketing campaign will be $11,000 at the end of year 1, $9,000 at the end of year 2, and $6,000 at the end of year 3. What is the annual equivalent worth of this marketing campaign over the next three years? The interest rate is 4.2% compounded annually."