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What does it mean to have 95 percent confidence in an interval estimate?
Wiki User
∙ 14y ago
It means that 95% of the values in the data set falls within 2 standard deviations of the mean value.
Wiki User
∙ 14y ago
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99 percent confidence interval Population mean 24.4 to 38.0 find the mean sample?
if the confidence interval is 24.4 to 38.0 than the average is the exact middle: 31.2, and the margin of error is 6.8
What percentage of time will the population proportion not be found within the confidence interval?
What percentage of times will the mean (population proportion) not be found within the confidence interval?
How do you calculate confidence interval?
Confidence intervals may be calculated for any statistics, but the most common statistics for which CI's are computed are mean, proportion and standard deviation. I have include a link, which contains a worked out example for the confidence interval of a mean.
When population distribution is right skewed is the interval still valid?
You probably mean the confidence interval. When you construct a confidence interval it has a percentage coverage that is based on assumptions about the population distribution. If the population distribution is skewed there is reason to believe that (a) the statistics upon which the interval are based (namely the mean and standard deviation) might well be biased, and (b) the confidence interval will not accurately cover the population value as accurately or symmetrically as expected.
Construct an 80 percent confidence interval for the true population mean given that the standard deviation of the population is 6 and the sample mean is 18?
THe answer will depend on whether the confidence interval is central or one-sided. If central, then -1.28 < z < 1.28 -1.28 < (m - 18)/6 < 1.28 -7.68 < m - 18 < 7.68 10.3 < m < 25.7
Is a 95 percent confidence interval for a mean wider than a 99 percent confidence interval?
No, it is not. A 99% confidence interval would be wider. Best regards, NS
When the sample size and sample standard deviation remain the same a 99 percent confidence interval for a population mean will be narrower than the 95 percent confidence interval for the mean?
Never!
TO ESTIMATE THE AVERAGE AGE OF STUDENTS A SAMPLE OF 50 PARTICIPANTS WAS OBTAINED, WITH A MEAN OF 16 AND A POPULATIONAL VARIATION OF 9, calculate:* POINT ESTIMATE OF THE MEANS* 95% AND 99% CONFIDENCE INTERVAL ESTIMATES FOR THE MEANS?
Point Estimate of the Mean: The point estimate of the mean is 16, since this is the sample mean. 95% Confidence Interval Estimate for the Mean: The 95% confidence interval estimate for the mean can be calculated using the following formula: Mean +/- Margin of Error = (16 +/- 1.96*(9/sqrt(50))) = 16 +/- 1.51 = 14.49 to 17.51 99% Confidence Interval Estimate for the Mean: The 99% confidence interval estimate for the mean can be calculated using the following formula: Mean +/- Margin of Error = (16 +/- 2.58*(9/sqrt(50))) = 16 +/- 2.13 = 13.87 to 18.13
What happens to the confidence interval as the mean decreases?
The confidence interval is not directly related to the mean.
99 percent confidence interval Population mean 24.4 to 38.0 find the mean sample?
if the confidence interval is 24.4 to 38.0 than the average is the exact middle: 31.2, and the margin of error is 6.8
What is confidence intervals in statistics?
The Confidence Interval is a particular type of measurement that estimates a population's parameter. Usually, a confidence interval correlates with a percentage. The certain percentage represents how many of the same type of sample will include the true mean. Therefore, we would be a certain percent confident that the interval contains the true mean.
What does a confidence interval for a population mean constructed from sample data show?
A confidence interval of x% is an interval such that there is an x% probability that the true population mean lies within the interval.
When comparing the 95 percent confidence and prediction intervals for a given regression analysis what is the relation between confidence and prediction interval?
Confidence interval considers the entire data series to fix the band width with mean and standard deviation considers the present data where as prediction interval is for independent value and for future values.
Compute the population mean margin of error for a 99 percent confidence interval when sigma is 4 and the sample size is 36?
The mean plus or minus 2.576 (4/sqr.rt. 36)= 1.72 So take your average plus or minus 1.72 to get your confidence interval
When determining the 95 percent confidence interval for a population mean with known sigma the value of the critical value of z is equal to?
1.96
Compute the population mean margin of error for a 90 percent confidence interval when sigma is 4 and the sample size is 36?
1.0966
What percentage of time will the population proportion not be found within the confidence interval?
What percentage of times will the mean (population proportion) not be found within the confidence interval?
