SOLUTION: Your process requires a fitting with a pitch diameter of 0.4 +/- 0.001 inch. You have been approached by ACME Fitting Co. to buy your fittings from them. Their fittings have diamet

Algebra ->  Probability-and-statistics -> SOLUTION: Your process requires a fitting with a pitch diameter of 0.4 +/- 0.001 inch. You have been approached by ACME Fitting Co. to buy your fittings from them. Their fittings have diamet      Log On


   

Question 1002323: Your process requires a fitting with a pitch diameter of 0.4 +/- 0.001 inch. You have been approached by ACME Fitting Co. to buy your fittings from them. Their fittings have diameters which are normally distributed with a mean of .4008 and a standard deviation of .0004.
What proportion of their product is expected to be within your tolerances?
I don't really know where to start with this, so I need some help. Thank you.:)
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Your process requires a fitting with a pitch diameter of 0.4 +/- 0.001 inch. You have been approached by ACME Fitting Co. to buy your fittings from them. Their fittings have diameters which are normally distributed with a mean of .4008 and a standard deviation of .0004.
What proportion of their product is expected to be within your tolerances?
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Sketch a normal curve with mean = 0.4008
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Sketch the area under the curve between 0.3999 and 0.4001
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Find the z-values:
z(0.3999) = (0.3999-0.4008)/0.0004 = -.025
z(0.4001) = (.4001-0.4008)/0.0004 = -1.75
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P(0.3999 < x < 4.001) = P(-1.75< z < -0.025) = normalcdf(-1.75,-0.025) = 0.45
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Ans 45%
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Cheers,
Stan H.