For this test, you'll need two Means (or averages) you want to compare, their corresponding Standard Deviations, and their corresponding Sample Bases. Samples are assumed to be uncorrelated. Significance is based on a two-sided test. Select the Confidence Level. Then input the Mean, Standard Deviation and Base for both Sample 1 and Sample 2. Click on "Solve" and the result will tell you if the difference is significant at the confidence level you've selected. Enter the values below Select Confidence Level: 85%     90%     95%     98% Sample 1 Sample 2 Mean Mean   Standard Deviation Standard Deviation   Base Base       Result: