Thank you for writing.
I have prepared a sample project for you where I have implemented your scenario. Please have a look at it and write back should you have any questions. In the project I use the RadGridView ViewRowFormatting for the styling the rows (the back color of the rows) and the GroupSummaryEvaluate to calculate the values for the summary rows.
I hope this will be useful for you. Again, should you have further questions do not hesitate to write back.
the Telerik team