First, you will want to know the method of how the tax on line 44 is being calculated.

You can see this by going to Tax Tools (on the left in the margin), then clicking on Tools and then "View Tax Summary". The federal summary will appear, but this is not useful for you; instead, on the left, click on Preview my 1040 - this will show you a copy of the completed 1040. 

On this previewed 1040, if you will scroll down to between lines 43 and 44, you will see the Tax Smart Worksheet. Here you will find the method of how the tax was calculated. This alone may give you enough information.

However, Online TurboTax users cannot see many of the worksheets until they pay for the product; Desktop users can see all forms and worksheets all the time, because they paid for the product before downloading it.

Thus, after you pay for the product and create a PDF version of the tax return (but this can be before you file), you can go look for these worksheets. The most common one after the Tax Tables is the "Qualified Dividend/Capital Gain Worksheet", which is created if you have qualifying dividends or capital gains (these are both taxed at a lower rate than ordinary income).