## 1.7 ANSERED QUESTIONS

#1 Draw the X, R, and s charts for the data below, using exact calculations: Then calculate the Control Limits using approximate techniques. #2 The data below was collected for a factory that manufactures telephones. Each day they make 10,000 phones, inspect 500, and expect to find 4 nonconforming (e.g. sometimes a button is put in upside down). The chart below lists nonconformity data for the previous week. Select the appropriate type of control chart, and plot the data. #3 Use a Frequency Division Analysis Sheet and 2 other methods to determine if the data listed below is normal.

5, 7, 4, 3, 5, 9, 6, 4, 6, 7, 2, 3

a) what is the difference between the two histograms below? b) Give a practical example of what a bi-modal distribution would indicate in quality control.

c) Describe the difference between Cp and Cpk.

d) How can Design of Experiments help an engineer improve a process?

e) Why would a single sampled plan be preferred to a double sampled Lot Acceptance Plan. Use an example in your answer.

f) Give a single sampling plan for a sample of 188 with an Acceptance Quality Level (AQL) of 0.4.

#5 Draw the Operating Characteristic (OC) curve for a batch of 10,000 with a sample size of 30, and a non-conforming reject level of 2. Identify the producers risk when a quality of 2% nonconforming is produced.

#6

a) Develop an Ishikawa diagram to identify problems when painting a house.

b) make a tally sheet based on your Ishikawa diagram, and suggest some data.

c) Draw a Pareto chart of the data.

a) What is meant by grouped and ungrouped data?

b) What is a mode? Give an example.

c) Describe the Instant Time Method

d) What problems can be seen in this control chart? #8 Is this data normal? #9 For the data in question #8 draw an X and R chart