Date and Time issues in Excel 2013

Hello, hopefully someone much smarter than myself can assist me with this problem. My apoligies in advance for such a long post


I am working on a call center report. In column A I have a list of agent names. Column B is the total calls taken by each agent for a given week. Column C contains the total logged in hours for the same week. In column D, I would like to divide column C by 8 to arrive at a decimal number showing total days worked in the week, assuming a day worked is 8 hours (this will equalize reporting for part time agents). Finally I would like to divide total calls by days worked to arrive at total calls per day. I need to do this for hundreds of rows.

The main issue I have is that the data in column C (for example 34:12:29) is supposed to be total "hh:mm:ss", but Excel thinks the data is "mm\dd\yyyy hh:mm:ss" (1/1/1900 10:12:29 AM in this example). I want it to display as 34.xx hours. I've attached a sample workbook for reference.

So, the root of my issue, how can I get excel to easily convert the data in column C to a decimal number of total hours? Thanks in advance for your replies.