STATISTICAL TECHNIQUES AND TOOLS
TESTS OF SIGNIFICANCE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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An engineer designs an improved light bulb. The previous design had an average lifetime of 1200 hours. The new bulb had a lifetime of 1201 hours, using a sample of 2000 bulbs. Although the difference is quite small, the effect was statistically significant. The explanation is that
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new designs typically have more variability than standard designs
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the mean of 1200 is large
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the new bulbs last longer than the old bulb
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the sample size is very large
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Explanation:
Detailed explanation-1: -The mean lifetime of a sample of 25 bulbs is found as 1550 hours with a SD of 120 h.
There is 1 question to complete.