This applet allows the student to change the numbers within a 2x2 contingency table. A tree diagram is displayed. When the compute button is clicked, the probabilities in the tree diagram are updated. The method of entry for row and column labels (and for data) is the same as for the contingency table applet, but the tree applet is restricted to 2 rows and 2 columns. Note that very long row and column labels may run over and look bad.
Tree Diagram Applet
How it works: Enter numbers in the interior of the table above. As you do so, the marginal row and column totals are updated continuously. Click the compute button to calculate the relevant probabilities and place them on the tree diagram.
<param name=rowlabels value="Pass Test 1,Fail Test 1" > - the
row labels for the contingency table (corresponding to the first split of
<param name=columnlabels value="Pass Test 2,Fail Test 2"> - the column labels for the contingency table (corresponding to the second split of the tree.
<param name=data value="35 21,16 90"> the initial data to appear in the table, row by row. There should be a space between numbers within a row, and a comma separating rows.