Bruce invested $12,000 in a mutual fund 5 years ago. he received a dividend check for $1,000 after the first year. He received $750 after the second year. At the end of the 3rd year he received a check for $1,500. after the 4th year he collected $750. His final dividend check of $1,000 was received at the end of the 5th year. assume that Bruce sold the mutual fund at the end of the 5th year for $18,000. what is Bruce's internal rate of return of this investment?