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In: Statistics and Probability

The life of a 9-volt battery is said to follow a Normal distribution. A sample of...

The life of a 9-volt battery is said to follow a Normal distribution. A sample of 75 batteries is tested and a mean life of the sample is found to be 50.25 hours with a standard deviation of 1.5 hours. Use α = 0.05.

(a) Is it believable that mean battery life exceeds 50 hours?

(b) Find the P-value for the test conducted in part a.

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