STATISTICAL TECHNIQUES AND TOOLS
CONFIDENCE INTERVALS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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A random sample of 42 textbooks has a mean price of $114.50 and a standard deviation of $12.30. Find a 98% confidence interval for the mean price of all textbooks.
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(111.38, 117.62)
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(110.08, 118.92)
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(110.78, 118.22)
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(109.61, 119.39)
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Explanation:
Detailed explanation-1: -The sample mean plus or minus 1.96 times its standard error gives the following two figures: This is called the 95% confidence interval, and we can say that there is only a 5% chance that the range 86.96 to 89.04 mmHg excludes the mean of the population.
Detailed explanation-2: -A range of possible values for the population mean that is centered about the sample mean. What does a 95% confidence interval indicate? That you are 95% confident that the population mean falls within the confidence interval.
There is 1 question to complete.