# 17.3.2.1 The Two-Sample T-Test Dialog Box

## Supporting Information

To open the Two-Sample t-Test dialog box:

1. With a worksheet active, click Statistics: Hypothesis Testing: Two-Sample t-Test.

## Recalculate

Recalculate Controls recalculation of analysis results None Auto Manual For more information, see: Recalculating Analysis Results

## Input

Indexed The input data consists of one sample data column and one grouping column. For help with range controls, see: Specifying Your Input Data Group Range The grouping column. Note that the grouping column will be set as categorical if Text column. Data Range The sample data column. The input data consists of two sample data columns. For help with range controls, see: Specifying Your Input Data 1st Data Range The first sample column. 2nd Data Range The second sample column. Summarized Data is mean, standard derivation and sample size prepared for samples 1st Data The first summarized data. 2nd Data The second summarized data.

## t-Test for Mean

Test Mean The hypothetical mean to be tested (0 if testing equality of means). The null hypothesis: No difference between Mean1 and Mean2. The alternate hypothesis: Mean1 - Mean2 <> Test Mean Difference Used for two-tailed two-sample test. Mean1 and Mean2 differ. Mean1 - Mean2 > Test Mean Difference Used for an upper-tailed two-sample test. Test Mean1 is greater than Mean2. Mean1 - Mean2 < Test Mean Difference Used for a lower-tailed two-sample test. Test Mean1 is less than Mean2. Specify the significance level. Compute confidence intervals for the differences of the means. For computation details, see Algorithms (Two-Sample T-Test). Enter space-separated confidence levels. This option is only available when Confidence Interval(s) is chosen.

## Power Analysis

Actual Power Compute the power of the test (the probability of rejecting the null hypothesis when it is false). Only available when Hypothetical Power and/or Actual Power are checked. This is the significance level (alpha value) for power computation. Compute the power of the test at various sample sizes. Only available when Hypothetical Power is checked. Specify hypothetical sample size(s) for power computation.

## Plots

Histogram Create a histogram. Create a box chart. Note that for the histograms, layers will be arranged vertically. For box chart, layers will be arranged horizontally.

## Outputs

For help with the range controls, see: Output Results

Results Log Output Select to output results to the Results Log. Specify a worksheet for output of plotted data (Origin generates tabular data when plots are created). Specify the worksheet for output of test results.