T-Test for Single Means - Quick tab

Select the Quick tab of the T-Test for Single Means dialog box to access options to specify the reference value to use when performing a t-test for single means.

For more options, including a variety of plots that enable you to visualize the distribution of the variable, use the Advanced tab.

Summary: T-tests

Options on this button:

  • Compute the t-tests for single means
  • Display the results in a spreadsheet.

The detail and formatting of the results depend on the selections made on the Options tab.

Reference values

When you have selected more than one variable on the Variables button, use the options in this group box to specify whether to test all variables against the same hypothesized mean, or to test each variable against a different (user-specified) mean.

Test all means against

This option:

  • Lets you specify the reference value in the corresponding edit field to test each variable against the same reference value (or hypothesized mean).
  • Performs a separate test for each variable.

    To test the hypothesis that the means for all variables are equal, use ANOVA/MANOVA.

Test means against different user-defined constants

  • Select this option button to specify different reference values for each t-test (or variable).
  • Click the Specify button (see description below) to specify values.

Specify

  1. Click this button to display the Select reference values dialog box.
  2. Specify a separate reference value for each selected variable.

    The Test means against different user-defined constants option button must be selected for this button to be available.

Box & whisker plot

Click this button to produce a box and whisker plot for the selected variables.

Box and whisker plots summarize the distribution of each variable. Specifically, each variable is represented by one box and whisker component, which is made up of three parts:

  • A central circle to indicate the mean
  • A box to indicate the mean plus/minus the standard deviation
  • Whiskers around the box to indicate the mean plus/minus 1.96*standard deviation (so if your data follows the normal distribution, 95% of your data should fall within the whiskers).