Statistical Applets Confidence Intervals

A level C confidence interval for a parameter is an interval computed from sample data by a method that has probability C of producing an interval containing the true value of the parameter. In this applet we construct confidence intervals for the mean (μ) of a Normal population distribution. Each interval is based on a SRS of size n. The dot marks the sample mean, which is the center of the interval. The lines on each side of the dot span the confidence interval. The total number of SRSs, the number that “hit” (i.e., the confidence interval contained μ), and the percent hit are tallied for you.	Set the desired confidence level and sample size with the sliders, then click SAMPLE to take a sample. On the right you'll see the sampled values as small yellow dots; the large dot will show the sample mean, and the lines on each side of this dot span the confidence interval. Click SAMPLE 25 to take 25 samples all at once. Intervals that contain the population mean μ ("hits") will be colored gray; "misses" will be colored red. Click on any confidence interval to show the sample data that the interval is based on. The Confidence Level (C) slider may be adjusted after generating samples to view the changes in the confidence intervals.

Statistical Applets

Confidence Intervals

A level C confidence interval for a parameter is an interval computed from sample data by a method that has probability C of producing an interval containing the true value of the parameter. In this applet we construct confidence intervals for the mean (μ) of a Normal population distribution. Each interval is based on a SRS of size n. The dot marks the sample mean, which is the center of the interval. The lines on each side of the dot span the confidence interval. The total number of SRSs, the number that “hit” (i.e., the confidence interval contained μ), and the percent hit are tallied for you.

Set the desired confidence level and sample size with the sliders, then click SAMPLE to take a sample. On the right you'll see the sampled values as small yellow dots; the large dot will show the sample mean, and the lines on each side of this dot span the confidence interval. Click SAMPLE 25 to take 25 samples all at once. Intervals that contain the population mean μ ("hits") will be colored gray; "misses" will be colored red. Click on any confidence interval to show the sample data that the interval is based on. The Confidence Level (C) slider may be adjusted after generating samples to view the changes in the confidence intervals.