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If you have a 99 confidence interval what would your confidence level and alpha for it be?
Wiki User
∙ 6y ago
Confidence level 99%, and alpha = 1%.
Wiki User
∙ 6y ago
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What is the confidence interval for 85 percent?
it would be with a level of significance of 0.15.
What would happen to the width of the confidence interval if the level of confidence is lowered from 95 percent to 90 percent?
decrease
What is a confidence interval in statistics?
When you calculate a statistic the result is not going to be perfectly accurate because of random errors in your observations. You therefore can give the result as one value along with a confidence interval (CI) around it. There are two interpretations of a CI. One interpretation is that you can be confident, with the stated level of confidence, that the true value of your statistic lies within the CI. The other interpretation is that if you repeated your experiment then, for the stated percentage of cases, the statistic would lie within the CI.
Does standard deviation effect the alpha level?
Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!
Is it true that the wider the confidence interval the less precise is the estimate?
All things being equal, a wider confidence interval (CI) implies a higher confidence. The higher confidence you want, the wider the CI gets. The lower confidence you want, the narrower the CI gets The point estimate will be the same, just the margin of error value changes based on the confidence you want. The formula for the CI is your point estimate +/- E or margin of error. The "E" formula contains a value for the confidence and the higher the confidence, the larger the value hence the wider the spread. In talking about the width of the CI, it is not correct to say more or less precise. You would state something like I am 95% confident that the CI contains the true value of the mean.
What is the confidence interval for 85 percent?
it would be with a level of significance of 0.15.
What would happen to the width of the confidence interval if the level of confidence is lowered from 95 percent to 90 percent?
decrease
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
Does the population mean have to fall within the confidence interval?
No. For instance, when you calculate a 95% confidence interval for a parameter this should be taken to mean that, if you were to repeat the entire procedure of sampling from the population and calculating the confidence interval many times then the collection of confidence intervals would include the given parameter 95% of the time. And sometimes the confidence intervals would not include the given parameter.
What are the advantages of a small confidence interval in statistics?
The smaller the confidence interval, the more certain you are of the answers. Remember confidence level and confidence interval (margin of error) are 2 separate things. So if you are using an industry standard confidence level of 95% and 5% margin of error in a standard statistical table, then you could say, for example, with 95% certainty that 60% of those polled would vote for John McCain. Another way of saying this is even though you did not poll everyone (if you did, it would then become a very expensive census), you can say with a high degree of certainty (95% certainty) that 55% to 65% of those polled will vote for Johnny (sadly).
What happen to confidence interval if increase sample size and population standard deviation simultanesous?
The increase in sample size will reduce the confidence interval. The increase in standard deviation will increase the confidence interval. The confidence interval is not based on a linear function so the overall effect will require some calculations based on the levels before and after these changes. It would depend on the relative rates at which the change in sample size and change in standard deviation occurred. If the sample size increased more quickly than then standard deviation, in some sense, then the size of the confidence interval would decrease. Conversely, if the standard deviation increased more quickly than the sample size, in some sense, then the size of the confidence interval would increase.
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.
Confidence level and significance level?
I have always been careless about the use of the terms "significance level" and "confidence level", in the sense of whether I say I am using a 5% significance level or a 5% confidence level in a statistical test. I would use either one in conversation to mean that if the test were repeated 100 times, my best estimate would be that the test would wrongly reject the null hypothesis 5 times even if the null hypothesis were true. (On the other hand, a 95% confidence interval would be one which we'd expect to contain the true level with probability .95.) I see, though, that web definitions always would have me say that I reject the null at the 5% significance level or with a 95% confidence level. Dismayed, I tried looking up economics articles to see if my usage was entirely idiosyncratic. I found that I was half wrong. Searching over the American Economic Review for 1980-2003 for "5-percent confidence level" and similar terms, I found: 2 cases of 95-percent significance level 27 cases of 5% significance level 4 cases of 10% confidence level 6 cases of 90% confidence level Thus, the web definition is what economists use about 97% of the time for significance level, and about 60% of the time for confidence level. Moreover, most economists use "significance level" for tests, not "confidence level".
What is a confidence interval in statistics?
When you calculate a statistic the result is not going to be perfectly accurate because of random errors in your observations. You therefore can give the result as one value along with a confidence interval (CI) around it. There are two interpretations of a CI. One interpretation is that you can be confident, with the stated level of confidence, that the true value of your statistic lies within the CI. The other interpretation is that if you repeated your experiment then, for the stated percentage of cases, the statistic would lie within the CI.
What is the confidence level on the Kaufman test of educational achievement?
The confidence interval (this is the correct term) is a prediction made on an academic achievement test. The idea is that if the student was tested again the authors of the test feel that they can be confident that the student's score would fall within the range of the interval. Often, you'll see a number in percent such as 95%, and then a range of scores below it. Most academic achievement tests have a mean of 100, so the score will be somewhere in the range of the test. The number is based on a comparison between that student and the norm group that the test was tested on. The higher the percent of the confidence interval, the more reliable the test is.
Does standard deviation effect the alpha level?
Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!Yes.For some tests, such as the Fisher F-test, the test statistic is an estimate of the variance. If the alpha level was not affected, the test would be no use at all!
Is it true that the wider the confidence interval the less precise is the estimate?
All things being equal, a wider confidence interval (CI) implies a higher confidence. The higher confidence you want, the wider the CI gets. The lower confidence you want, the narrower the CI gets The point estimate will be the same, just the margin of error value changes based on the confidence you want. The formula for the CI is your point estimate +/- E or margin of error. The "E" formula contains a value for the confidence and the higher the confidence, the larger the value hence the wider the spread. In talking about the width of the CI, it is not correct to say more or less precise. You would state something like I am 95% confident that the CI contains the true value of the mean.
