STATISTICAL TECHNIQUES AND TOOLS
CONCEPT OF POINT AND INTERVAL ESTIMATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The lifetime of a certain type of battery is known to be normally distributed with a standard deviation of 20 hours. A sample of 50 batteries had a mean lifetime of 120.1 hours. It is desired to construct a 99% confidence interval for the mean lifetime of this type of battery.What is the Confidence Interval to one decimal place?
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(114.5, 125.6)
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(112.8, 127.4)
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(112.82, 127.38)
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(114.56, 125.64)
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Explanation:
Detailed explanation-1: -10.8 is 2 standard deviations. . represents approximately 48% of the data. A battery lifetime of 561 days is 1 standard deviation above the mean lifetime. Batteries will last longer than 561 days 15.9% of the time.
Detailed explanation-2: -The life expectancy of batteries has a normal distribution with a mean of 350 minutes and a standard deviation of 10 minutes.
There is 1 question to complete.