A vaccine manufacturer hires you as a quality inspector at a hospital. In particular, the manufacturer suspects that the fridge in the hospital does not meet the standard. You are going to focus on an important determinant of vaccine quality - the storage temperature. The temperature is supposed to be 93F. Anything between 90F and 96F is acceptable to the patient. On Apr 1", you randomly sampled one-dose vaccine that the hospital stored, and measured the temperature. The temperatures (in F) are summarized in the following table: Sample ID Unit 1 Unit 2 Unit 3 Unit 4 X-bar R 1 91 89 91.00 3 2 87.75 4 3 88.50 7 4 5 5 5 3 90.75 6 91.00 7 87.50 3 91.25 5 6 7 8 9 10 323828339 91 90 87 94 28883%83%8 93 92 86 93 90 89 93 93 86 91 8399988883 86 86 91 91 87 23898%%%89 92 9 10 90 86 90 86 93 a. (4 points) Fill the blanks in the table above. In other words, compute the X-bar value and R value for the 6th Sample. b. (4 points) Compute X-bar-bar and X control limits. 88 Sample Size 2 4 89.75 90.00 A2 D3 D4 d2 1.88 0 3.268 1.128 0.729 0 2.282 2.059 0.337 0.184 1.816 2970 0.308 0.223 1.777 3.078 c. (6 points) Draw the X-bar control chart. Based only on the X-bar control chart, is the process in control? Control chart: (4 points) 95 93 91 89 87 85 2 3 Is the process in control: (2 points) 4 6 8 9 e. (3 points) After adjusting the thermostat, what is the process capability index Co? 10 Sample Index d. (3 points) There is a thermostat that controls the average storage temperature of the fridge. Based on the data, how should you adjust the thermostat? (Don't overthink! This is simple question.)