Question

Create a Control Limit chart for the following: You are a manager at RadioTag Inc., a maker of RFID tags for US military and private use (e.g., Wal Mart). Your process assembles radio id tags to certain specifications – 95.5 confidence intervals, however as they come off the assembly line a test is run on each tag to determine whether the frequency works or does not (hint the data are dichotomous distributed binary). Below are the data you collected over a 2-week period:                                                                                                                                                                                                                                                                                                                                                                GRAPH GOES UNDER THIS

Day sample size        non-working tags

1                      100                         15

2                      100                         13

3                      100                         12

4                      100                         11

5                      100                         16

6                      100                         19

7                      100                         5

8                      100                         8

9                      100                         19

10                   100                         15

11                   100                         2

12                   100                         6

13                   100                         9

14 100                         10

1.         P bar =

SD of P bar =

UCLP Bar =

LCLP bar =

B) Graph and Plot the data. Round answers to three places.

Clearly identify the P bar, s.d. of Pbar, UCL, LCL (make sure the graph elements are labeled) and identified in A above.

C) Compare p value to a. What is the result?

Answer 1

Answer: Date: -17/06/2019 A) Sample No-working Defect Day Size |Proportion tags 100 15 0.15 1 100 2 13 0.13 100 12 0.12 3 100 4 11 0.11 100 16 0.16 5 100 19 0.19 100 0.05 7 5 100 100 0.08 8 19 9 0.19 0.15 10 100 15 0.02 100 11 2 100 12 0.06 0.09 6 100 13 9 14 10 100 0.1 Total 160 P-bar = Number of defects/(No of sample*sample size) = 160/(14*100) = 0.114286 Standard deviati on of P-bar sqrt((p*(1-p))/n) where n sample size sqrt((0.114286*(1-0.114286))/100) 0.031816 95.5 confidence interval) z-sccore for 95.5% CI 2 (As 2 sigma UCL(P-bar) = p-bar + z*Standard deviation of P-bar = 0.114286 + 2*0.031816 = 0.177918 LCL(P-bar) = p-bar - z*Standard deviation of P-bar = 0.114286 - 2*0.031816 = 0.050654

B) P-chart 0.2 0.18 0.16 0.14 0.12 0.1 0,08 0.06 0.04 0.02 0 1 2 3 4. 5 6 7 10 11 12 13 14 Defect Proportion P-bar LCL UCL

Graph Data Defect Proportion 0.178 LCL P-bar UCL 0.15 0.114 0.051 0.13 0.1142860.0506540.177918 0.1142860.0506540.177918 0.1142860.0506540.177918| 0.1142860.0506540.177918 0.1142860.0506540.177918 0.1142860.0506540.177918| 0.1142860.0506540.177918| 0.1142860.0506540.177918 0.1142860.0506540.177918 0.1142860.0506540.177918 0.1142860.0506540.177918 0.1142860.0506540.177918| 0.1142860.0506540.177918| 0.12 0.11 0.16 0.19 0.05 0.08 0.19 0.15 0.02 0.06 0.09 0.1 C) Comparing P-values in the graph sample 6,9 and sample 11 breached the control limits we can see the process is not in control as