STATISTICAL TECHNIQUES AND TOOLS
CONFIDENCE INTERVALS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Mr. Kellar’s class would like to estimate the mean number of times females interact with Instagram at Northland. Find a 95% confidence interval based on the data students gathered:10, 15, 20, 8, 7, 5, 15, 20, 7, 8, 9, 6
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(7.7, 14.9)
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(7.6, 14.1)
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(7.5, 14.2)
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(7.8, 15)
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Explanation:
Detailed explanation-1: -We use ‘2’ as the multiplier because we want a 95% confidence interval. The ‘95’ part of the 68-95-99.7 rule for the Normal distribution explains why 2 times the SE corresponds to a 95% interval. We can have a narrower interval if we are prepared to accept a lower level of confidence.
Detailed explanation-2: -n = N*X / (N + X – 1), where, X = Z/22 * 2 / MOE2, and Z/2 is the critical value of the Normal distribution at /2 (e.g. for a confidence level of 95%, is 0.05 and the critical value is 1.96), MOE is the margin of error, 2 is the population variance, and N is the population size.
There is 1 question to complete.