Nth Row and Sub total

To best describe or illustrate your problem you would be better off attaching a dummy workbook, the workbook should contain the same structure and some dummy data of the same type as the type you have in your real workbook - so, if a cell contains numbers & letters in this format abc-123 then that should be reflected in the dummy workbook.

If needed supply a before and after sheet in the workbook so the person helping you can see what you are trying to achieve.

Doing this will ensure you get the result you need!

I'm still not clear on what you want to achieve. Can you manually mock up a sample of the expected result?

cheers,

Ah, now I see. These formulas are summing rows, not columns.

Create the first row with the sum formula, copy the whole row (by selecting the row header), then use Insert Copied Cells to paste into their new locations (a new row will be inserted)

Perhaps simplest to just use Excel's inbuilt Subtotal functionality:

Highlight A:H and apply Data -> Subtotal as follows:

At Each Change In: Half Hour

Use Function: Sum

Add Subtotals To: Calls, Abandoned Calls, Avg Speed of Answer, Avg Abandoned Time

The other alternative would be to use a Pivot Table to analyse the Data

Prior to adding the Subtotals...

Type 0 into a blank cell - copy it - highlight your "Time" cells and run Paste Special -> Operation: Add

If you have just one column for the above you can also try highlight the column and run Data -> Text to Columns -> click Finish.
(TtC is limited to one column at a time so for multiple the Paste Special route can be preferable)

You might want to format as [h]:mm if any cell (incl. sub totals) can exceed 24 hours.