STATISTICAL TECHNIQUES AND TOOLS
CONFIDENCE INTERVALS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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approximately 1170
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approximately 1050
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approximately 1500
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approximately 40
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Detailed explanation-1: -d) A 95% confidence interval indicates that there is 95% certainty that a population mean lies in a given range of values. is the correct answer.
Detailed explanation-2: -A 99 percent confidence interval would be wider than a 95 percent confidence interval (for example, plus or minus 4.5 percent instead of 3.5 percent). A 90 percent confidence interval would be narrower (plus or minus 2.5 percent, for example).
Detailed explanation-3: -Answer & Explanation For a 95% confidence interval, z* is 1.96. Rounding up to the nearest whole number, the sample size required is 147. Therefore, we need to select at least 147 observations from the population to construct a 95% confidence interval with a margin of error of 8.