This applet estimates the confidence interval for a mean.
How to use the applet
- Choose a sample size,
, from
the drop down box. Choose a sample size between 2 and 15.
- Enter a level,
, into the
cell. Note, the cells in this applet act like a spreadsheet
application; to change an entry, click on it, delete the current
value, type a new one, and then press enter.
- Click "Generate New Data." A sample of size
will be displayed below the
button in the row labeled "Data," and the sample mean,
, is
automatically calculated and displayed below the data.
- You may edit the data in the row labeled "Data." Remember that
these cells behave like a spreadsheet application, so press enter
after you have edited a cell. The sample mean,
, is updated after you
edit a cell and press enter.
- Choose a bootstrap sample size of
or
,
and click "Generate Bootstrap Samples."
- A histogram of the means of the bootstrap samples is plotted.
To view the bootstrap samples and their means, click "View
Bootstrap Samples," and a new window will pop up.
- Below the plot, the confidence intervals are computed by two
methods. They are Method
I:
and Method II:
. The plot is shaded to highlight the confidence
interval computed via Method I.
The applet