FirstTax is a chain of storefront tax preparation offices located throughout the city. Roland McGee, the company's director of customer service, is speaking with Veronica Voss, the company's head of human resources, about the customer satisfaction surveys from the latest tax season. Each customer rates his or her tax preparer on a scale of 1 to 10, with 10 indicating "delighted" and 1 indicating "pissed off." FirstTax is a chain of storefront tax preparation offices located throughout the city. Roland McGee, the company's director of customer service, is speaking with Veronica Voss, the company's head of human resources, about the customer satisfaction surveys from the latest tax season. Each customer rates his or her tax preparer on a scale of 1 to 10, with 10 indicating "delighted" and 1 indicating "pissed off." VERONICA: That's not entirely fair. A preparer can be providing level-8 service in general but happen to get a few grumpy or hard-to-please customers. We should really be asking whether Bob's average performance is significantly less than 8. Let's assume that Bob's 64 ratings represent a random sample from the population of possible customers Bob could have served. I calculate that the standard deviation of his 64 ratings is 3.00. That should be enough for us to answer the "significance" question. Help Roland and Veronica by performing the following hypothesis test at the 5% significance level. Ho: = 8 versus Ha: < 8 Show all relevant calculations, draw a picture, and indicate the test-statistic and prob-value for the test. State your conclusion in terms of its implications about Bob's performance.