Rate of Return Calculation

So my 401k account states that I have a certain "Year-to-date Rate of Return" of 37% that so far I haven't been able to figure out. I finally found a page on their site describing how it's calculated and was wondering if y'all could help me convert it to work in excel.

I've provided a PDF of their calculation and an excel spreadsheet with their example that just needs to be filled in, also a second example to verify.

Example 1 is straight from the PDF and the "Ending Balance" is more than the sum of the contributions+beginning balance. Is this an error or is that including the interest and fees as well?

In Example 2, there is a second column that has the Fees + Interest.