Prepare a quality control chart from the following sequential, weekly cycle-time data from the manu- Guat’ COntrel Appendix)

facture of computer-tape storage devices. Use the historical mean cycle time and a 2 standard-deviation (LO 6)

upper and lower control limit. What does this chart indicate?

Week Average Cycle Time in Hours OO) Pein GOP ti a meres rie aig tata aaa a 55

<8 Shurpe ge ab gach ited de Pe pear Pipe eee emp Renan emer pene Ce 33 Bi oe Ee in et BOMEU EMOTE Rn SOONER PE Se Tr OD bee ears 93 Ieee canara acm SE Etr otCE ta Cat nTE Sen onc pree Bae area Pree metert 82 SORA Areal eo ene: foe teh) ates tees ae ate 49 AQUA! eAeROE SK) ei AAU, he WN REMAN ehcp etn 73 le eee Fee ee ELS ee be Mer na oe ee Be 88 AND) . esc MBe ev one soso De ERE OLE OC Cee 45 AS i rele pe rs ae er Ree eT SEA 69 LO oO ce aN ee ee eR a tao ao ane 36 AIS a te lie ie ti ee cae Maran reem eer pe han cd SS 101 ASP cce Er eee (Gost re een ey ero ee eee a 107 ANG( E e ea ko Oe RATE ERS EC CER OR ORC PEC COR nn EEE Oe 89 ANS) seh it nee RaGERRT EERE ORE OR DNRC COR ESE TG 74 AN) fo is 8 rat as eee an tat eR eh aeRO 64 Oem eaeeee er pen ie taenrcce ass eaiueat omer Sete G 55 15) ita apcive soap rea BURR GD EGE mr oe crime in odoe netic 52