Question

A dog food company packages their food in 40 lbs bags. After taking 9 samples of 6 bags and determining their process to be in control x -bar -bar = 42.5875

and R bar = 1.2937

1) compute the upper control limits / lower control limits for both X and R

2) what is n in this situation

3) calculate the Natural Tolarence Limits

Answer 1

Solution:

(a) The formula for control limits are:

Here as the sample size is 6, so A₂ = 0.483

So,

UCL = 42.5875 + 0.483*1.2937 = 43.2123571 or 43.212

LCL = 42.5875 - 0.483*1.2937 = 41.9626429 or 41.962

(b) In this case, n = 6

(c) Formula:

Or, NTL = 42.5875 ± 3*(1.2937/2.534) (Refer the chart given above for d₂)

Or, NTL = 42.5875 ± 1.531610103

So, Natural Tolerance Limits are: (41.055889897, 44.119110103) or (41.056, 44.119)

End of the Solution...