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The capacities (in ampere-hours) were measured for a sample of 120 batteries. The average was 178...

The capacities (in ampere-hours) were measured for a sample of 120 batteries. The average was 178 and the standard deviation was 12.

a.)

Find a 95% lower confidence bound for the mean capacity of this type of battery. Round the answer to two decimal places.

b.) An engineer claims that the mean capacity is greater than 175 ampere-hours. With what level of confidence can this statement be made? Express the answer as a percent and round to two decimal places.

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milcah answered 10 months ago
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