Question 627275
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The Z-score for 10% or less is -1.28.  So


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ \frac{x\ -\ 26}{6}\ =\ 1.28]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x\ \approx\ 18.3]


Set the warranty period at 18 months.


John
*[tex \LARGE e^{i\pi}\ +\ 1\ =\ 0]
My calculator said it, I believe it, that settles it
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