STATISTICAL TECHNIQUES AND TOOLS
SAMPLING DISTRIBUTION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Which z-value is used for a 95% confidence interval?
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1.645
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1.96
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2.575
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2.33
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Explanation:
Detailed explanation-1: -The critical z-score values when using a 95 percent confidence level are-1.96 and +1.96 standard deviations. The uncorrected p-value associated with a 95 percent confidence level is 0.05.
Detailed explanation-2: -1.96 is used because the 95% confidence interval has only 2.5% on each side. The probability for a z score below −1.96 is 2.5%, and similarly for a z score above +1.96; added together this is 5%. 1.64 would be correct for a 90% confidence interval, as the two sides (5% each) add up to 10%.
Detailed explanation-3: -The value of z* for a confidence level of 95% is 1.96.
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