Question: In a law office, the average number of billed hours per week was 600 last year. In the first 16 weeks of this year, the average number of billed hours per week is 640 with a standard deviation of 86 hours. At the 10% level of significance, is there a significant amount of evidence to suggest that the average number of billed hours over the past 16 weeks has changed compared to last year’s average of 600?