Question #8 (10 points - a.) 6 points b.) 2 points c.) 2 points) Nancy is a waitress at Seventh Heaven Hamburgers. She wants to estimate the average amount each table leaves for a tip. A random sample of 5 groups was taken and the amount they left for a tip (in dollars) is listed below: $11.00 $7.00 $7.00 $4.00 $6.00 a.) Find a 90% confidence interval for the average amount left by all groups. (*round to the nearest cent*)