12 raw diamonds of 3 carets each are chosen for a demonstration of a new robotic diamond cutter. This robot has sensors that can detect the planes of the diamond where it is to be cut and can supposedly cut a larger caret diamond than a human diamond cutter can. The 12 diamonds cut for this demonstration had these carets: 1.1, 1.2, 1.4, 1.3, 1.3, 1.4, 1.3, 1.5, 1.2, 1.4, 1.1, 1.3
Please give the UPPER VALUE for a 90% confidence interval for the average caret diamond cut by the robot when starting with a 3 caret raw diamond. Please submit the answer with 2 decimal places.