Question 5.22: The lengths of bolts manufactured by a certain process are k...

Principles of Statistics for Engineers and Scientists

The lengths of bolts manufactured by a certain process are known to be normally distributed. In a sample of 30 bolts, the average length was 10.25 em, with a standard deviation of 0.20 em. Find a tolerance interval that includes 90% of the lengths of the bolts with 95% confidence.

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