Helen, a sociologist, is considering buying a new power lawn mower. It would save her 30 minutes of work a week, which she would use to see another client. Her fee is $16 per hour and she works 50 weeks a year. The lawn mower would cost $1,400. What would her IRR be if the mower was expected to last eight years? Express your figures on an annual basis and assume that her required rate of return is 9 percent.