Question

Problem 10-24 (Algo) A shirt manufacturer buys cloth by the 100-yard roll from a supplier. For setting up a control chart to manage the irregularities (e.g., loose threads and tears), the following data were collected from a sample provided by the supplier. SAMPLE IRREGULARITIES 2 4 3 6 4 4 5 2 6 6 7 5 8 4 9 3 10 5 6 a. Determine the c. S.UCL and LCL for a c.chart with z=2. (Leave no cells blank - be certain to enter "0" wherever required. Round your answers to 2 decimal places.) cbar b. Suppose the next five rolls from the supplier had two, two, six, two, and six irregularities. Is the supplier process under control? Yes No

Answer 1

blyes cbar = 4.5 Sc = 2.12 UCL I 8.74 LCL = 0. 26 of defects Average number per unit total number of defects number of samples + 6+5+4+3+ 5 = 6 + 4+6+4+2 - yoo 45 - 4.5 10 Standard deviation sp=ſo = √4.5 ~ 2.12 for z=2 the upper control limit = c + Zsp = 4.5+ 2x2.12 = (8.74) = 0.26) lower control limit =č - Zsp=4.5 - 2x2-12 under control Note: process is b) yes