SOLUTION: In the NASCAR racing industry ball bearings are automatically produced on a Kronar BBX machine and are known to be normally distributed. For one of the production lines, the mean d

Algebra ->  Probability-and-statistics -> SOLUTION: In the NASCAR racing industry ball bearings are automatically produced on a Kronar BBX machine and are known to be normally distributed. For one of the production lines, the mean d      Log On


   

Question 453762: In the NASCAR racing industry ball bearings are automatically produced on a Kronar BBX machine and are known to be normally distributed. For one of the production lines, the mean diameter is set at 20.00 mm (millimeters). The standard deviation, over a long period of time, was computed to be 0.150 mm. What percent of the ball bearings on this line will have diameters of 20.27 mm or more?
Found 2 solutions by edjones, stanbon:
Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
20.27-20.00=0.27
z=0.27/0.150=1.8
3.593%
.
Ed

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
For one of the production lines, the mean diameter is set at 20.00 mm (millimeters). The standard deviation, over a long period of time, was computed to be 0.150 mm. What percent of the ball bearings on this line will have diameters of 20.27 mm or more?
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z(20.27) =(20.27-20.00)/0.15 = 1.8
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P(x >= 20.27) = P(z >= 1.8) = 0.0359.. = 3.59%
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Cheers,
Stan H.