Probelm 10 7 and 10 8 Solution Needed

Question: #660

10-7 A shirt manufacturer buys cloth by the 100 yard roll from a supplier. For setting up a control chart to manage the flaws (e.g., loose threads and tears) the following data was collected from a sample pro-vided by the supplier.

SAMPLE 1 2 3 4 5 6 7 8 9 10
FLAWS 3 5 2 6 5 4 6 3 4 5

a. Using the data, set up a c-chart with z = 2.
b. Suppose the next five rolls from the supplier had three, two, five, three, and seven irregularities. Is the supplier process under control?

10-8 Resistors for electronic circuits are manufactured on a high-speed automated machine. The machine is set up to produce a large run of resistors of 1,000 ohms each.

To set up the machine and to create a control chart to be used throughout the run, 15 samples were taken with four resistors in each sample. The complete list of samples and their measured values are as follows:

(Use three-sigma control limits as in Exhibit 6.13.) Sample Number Reading (IN OHMS) 1 1,021 999 985 986 2 1,019 1,001 1,009 994 3 1,020 1,011 1,015 1,008 4 1,023 991 1,009 998 5 1,016 1,006 1,005 993 6 1,016 1,016 994 1,005 7 1,015 1,004 982 1,020 8 994 985 996 996 9 1,018 995 1,005 1,007 10 992 1,016 1,006 979 11 1,014 1,012 997 989 12 1,014 995 991 1,011 13 994 996 989 1,003 14 1,005 992 988 984 15 1,021 1,012 1,005 992 Required:

(a) Determine the , for a X chart and R chart. (Round your answers to 3 decimal places.)

(b) Determine the UCL, LCL for a X chart. (Round your answers to 3 decimal places.) UCL LCL

(c) Determine the UCL, LCL for a R chart. (Leave no cells blank - be certain to enter "0" wherever required. Round your answers to 3 decimal places.) UCL LCL

(d) What comments can you make about the process for the chart?