Problem 2: To reduce the costs associated with an accident and its consequences, returning the employee to work, even in a limited capacity is critical. The safety engineer wants management to understand the importance of managing the days it takes to return employees to work. To show their past performance, he wants to create an easy-to-understand chart for his bosses, so he decides to create an np chart.

1. Calculate the centerline and control limits for an np chart. Show your calculations.

2. Looking at the data, and using the values calculated in part B, are there any points that are out of control?

3. What is the number of days to return to work that can be expected in the future? (In other words, what is the process capability)?

Note, you do not need to graph the chart in Minitab

Subgroup	Sample Size n	Number of days to return to work (np)
1	10	6
2	10	14
3	10	6
4	10	3
5	10	8
6	10	22
7	10	4
8	10	3
9	10	24
10	10	2
11	10	6
12	10	17
13	10	1
14	10	5
15	10	6
16	10	3
17	10	2
18	10	6
19	10	16
20	10	1
21	10	2
22	10	1
	220	158