During the COVID-19 pandemic the Nation of Narnia is using about 600,000 masks a day. Some MPs accused the Health Department of the Nation of Narnia of providing substandard masks that dont fit well, smell bad and cause skin irritation. As a result, the Health Department of the Nation of Narnia inspected 250 masks each day randomly for nonconformities over the past 20 days. Using the following 20 days (Table 3) sample results for the number of nonconformities in 250 observations (n=250) each day, a) Calculate the proportion of nonconformities of the masks in each sample, and calculate three-sigma upper and lower control limits. b) Construct a control chart for the proportion of nonconformities of the masks using three-sigma limits. Is the process in control? Why? c) Would your conclusion in (2. b) change if you use two-sigma control limits? Why?

Table 3
Day	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20
Number of retests	20	10	2	6	8	6	4	0	16	2	8	4	0	6	24	10	14	4	4	10

Please solve not on excel