Business

Statistical process control and quality management

Problem 2

A

We know that the X=1.002, LTL=1-0.01, UTL=1+0.01, standard deviation=0.003,so we can calculate the

Cpk=Min{(1.002-0.99)/(3*0.003),(1.01-1.002)/(3*0.003)}=0.89

B

Problem 3

A

P=(3+1+2+3+1)/(15*10)=0.067

Sp=√[p(1-p)/n]=0.064

So

LCL=P+z*Sp=0.067+1.96*0.064=0.192

UCL=P-z*Sp=0.067-1.96*0.064=-0.058

B

Problem 5

If an inspector is hired, it cost $8 per hour,

Otherwise, it may cost 0.03*30*$10=$9 per hour.

So, an inspector should be hired.

Problem 6

|sample number |readings(in ohms) |avg |range |

|1 |1010 |991 |985 |986 |993 |25 |

|2 |995 |996 |1009 |994 |998.5 |15 |

|3 |990 |1003 |1015 |1008 |1004 |25 |

|4 |1015 |1020 |1009 |998 |1010.5 |22 |

|5 |1013 |1019 |1005 |993 |1007.5 |26 |

|6 |994 |1001 |994 |1005 |998.5 |11 |

|7 |989 |992 |982 |1020 |995.75 |38 |

|8 |1001 |986 |996 |996 |994.75 |15 |

|9 |1006 |989 |1005 |1007 |1001.75 |18 |

|10 |992 |1007 |1006 |979 |996 |28 |

|11...