Question

You are in charge of quality control for computer keyboards at Dell. You have data on twenty-five batches of keyboards, tracking five types of keyboard defects: key brightness, scissor mechanics, dusting, dead connections, and stuck keys. These data are given in the table below. Complete in Excel.

1a. For each defect type, find the average number of defects per batch. So, you should have an average defect rate for displays, another for color, and so on.

1b. For each batch, find the total number of defects (the sum of all five types). So, you should have one number for batch 1, another for batch 2, and so on.

1c. Sort the five columns of defects by descending average defect rate. The lowest rate should be on the right.

1d. Sort the batches by descending total defects. The batch with the highest total should be at the top. This will not affect the column sorting from the part 3 above.

1e. Create a Pareto chart showing the average defect rate for each of the five defect types. This will be a column chart, in descending left-to-right order, with each column and the axes labeled

	Defects
Batch	Key Brightness	Dead Connections	Dusting	Scissor Mechanics	Stuck Keys
1	4	1	1	0	2
2	2	2	0	0	3
3	3	5	2	1	1
4	3	0	0	2	2
5	3	0	1	2	3
6	2	0	2	0	1
7	3	3	1	2	2
8	1	1	0	0	2
9	0	1	0	3	0
10	2	1	2	1	0
11	2	3	1	3	2
12	1	1	2	2	0
13	1	2	4	0	0
14	2	1	0	1	0
15	1	2	2	2	4
16	0	1	1	3	1
17	1	2	0	0	1
18	3	3	0	2	2
19	1	0	3	0	3
20	2	1	2	0	0
21	1	3	0	3	0
22	2	3	0	0	2
23	1	2	1	3	6
24	0	3	2	0	0
25	2	4	2	1	0

Answer 1

1a Mean defects per batch for

(a) Key brightness = 43/25 =1.72

(b) Dead connections =1.8

(c) Dusting =1.16

(d) Scissor mechanics =1.24

(e) Stuck keys =1.48

2.

Batch	Key Brightness	Dead Connections	Dusting	Scissor Mechanics	Stuck Keys	Sum	Mean
1	4	1	1	0	2	8	1.6
2	2	2	0	0	3	7	1.4
3	3	5	2	1	1	12	2.4
4	3	0	0	2	2	7	1.4
5	3	0	1	2	3	9	1.8
6	2	0	2	0	1	5	1
7	3	3	1	2	2	11	2.2
8	1	1	0	0	2	4	0.8
9	0	1	0	3	0	4	0.8
10	2	1	2	1	0	6	1.2
11	2	3	1	3	2	11	2.2
12	1	1	2	2	0	6	1.2
13	1	2	4	0	0	7	1.4
14	2	1	0	1	0	4	0.8
15	1	2	2	2	4	11	2.2
16	0	1	1	3	1	6	1.2
17	1	2	0	0	1	4	0.8
18	3	3	0	2	2	10	2
19	1	0	3	0	3	7	1.4
20	2	1	2	0	0	5	1
21	1	3	0	3	0	7	1.4
22	2	3	0	0	2	7	1.4
23	1	2	1	3	6	13	2.6
24	0	3	2	0	0	5	1
25	2	4	2	1	0	9	1.8

1c

Batch	Dusting	Scissors M	Stuck keys	Key brightness	Dead connections
1	1	0	2	4	1
2	0	0	3	2	2
3	2	1	1	3	5
4	0	2	2	3	0
5	1	2	3	3	0
6	2	0	1	2	0
7	1	2	2	3	3
8	0	0	2	1	1
9	0	3	0	0	1
10	2	1	0	2	1
11	1	3	2	2	3
12	2	2	0	1	1
13	4	0	0	1	2
14	0	1	0	2	1
15	2	2	4	1	2
16	1	3	1	0	1
17	0	0	1	1	2
18	0	2	2	3	3
19	3	0	3	1	0
20	2	0	0	2	1
21	0	3	0	1	3
22	0	0	2	2	3
23	1	3	6	1	2
24	2	0	0	0	3
25	2	1	0	2	4

1d

Batch	Key Brightness	Dead Connections	Dusting	Scissor Mechanics	Stuck Keys	Sum
23	1	2	1	3	6	13
3	3	5	2	1	1	12
7	3	3	1	2	2	11
11	2	3	1	3	2	11
15	1	2	2	2	4	11
18	3	3	0	2	2	10
5	3	0	1	2	3	9
25	2	4	2	1	0	9
1	4	1	1	0	2	8
2	2	2	0	0	3	7
4	3	0	0	2	2	7
13	1	2	4	0	0	7
19	1	0	3	0	3	7
21	1	3	0	3	0	7
22	2	3	0	0	2	7
10	2	1	2	1	0	6
12	1	1	2	2	0	6
16	0	1	1	3	1	6
6	2	0	2	0	1	5
20	2	1	2	0	0	5
24	0	3	2	0	0	5
8	1	1	0	0	2	4
9	0	1	0	3	0	4
14	2	1	0	1	0	4
17	1	2	0	0	1	4

Note: As per policies, I can answer first 4 parts of a question. Inconvenience is regretted.