Where do you call methods for Scenario 1 and Scenario 2 is a little vague. The program directions talk about calling getDouble to have the user enter the deposit and rate in the main method. You'll do that for both scenarios which means four calls to getDouble.
Within the createTable method, you need to call computeBalance for scenario 1 and then again for scenario 2. Since you need to call computeBalance for each year, then think about a loop with calls to the computeBalance method in the body of the loop.