Confidence Intervals

Internet
Demonstrations

Up
Confidence Int. Ans.

You can link to a confidence intervals applet to determine whether an extended series of 95% or 99% confidence intervals cover a known population mean the specified percent of times.

The confidence intervals in this demonstration anticipate those discussed in the next chapter, when the sample standard deviation must replace the unknown population standard deviation. This feature causes the actual width of each confidence interval to vary depending on the value of the sample standard deviation for that particular confidence interval -- without, however, compromising the essential properties of confidence intervals discussed in the current chapter.

Observe that, as you extend the series of confidence intervals, the cumulative percent of true confidence intervals usually approaches – although, because of chance, doesn't actually equal -- the percent specified by the confidence coefficient.

• Read Instructions (printing a hard copy, if possible, for easy reference.)
• Click on "Begin" to start demonstration.
• When finished click on "Exercises," concentrating on questions 1-4. To check your responses, see Answers.