This page will perform a t-test for the significance of the difference between the observed mean of a sample and a hypothetical mean of the population from which the sample is randomly drawn. Procedure:
Entering Data Directly into the Data Entry Field:T
After clicking the cursor into the text area labeled Data Entry, enter the values for the sample in sequence, pressing the carriage return key after each entry except the last. (On a Macintosh platform, the carriage return key is labeled 'Return'; on a Windows platform it is labeled 'Enter.') Importing Data via Copy & Paste:T
Within the spreadsheet application or other source of your data, select and copy the column of data for the sample. Then return to your web browser, click the cursor into the text area for Data Entry and perform the 'Paste' operation from the 'Edit' menu.T Data Check:T
Make sure that the final entry in the list is not followed by a carriage return. (A carriage return after the final entry will be interpreted as an extra data entry whose value is zero. Importing data via the copy and paste procedure will almost always produce an extra carriage return at the end of a column.) After all values for the sample have been entered, click the cursor immediately to the right of the final entry in the list, then press the down-arrow key. If an extra line is present, the cursor will move downward. Extra lines can be removed by pressing the down-arrow key until the cursor no longer moves, and then pressing the 'Backspace' key (on a Mac platform, 'delete') until the cursor stands immediately to the right of the final entry.T When all sample values have been entered, click the button labeled 'Calculate.'
one-tailed