These statistics are interrelated (generally DOM indicates market demand, and close price ratio reflects that) but, I've not seen the differential between the two represented before, but would be interested in where you've seen it used.
Would you post it here if you can?
DOM can be looked at in a few different ways, here are two big differences:
Let's look at an example. A Home goes on the market and after 5 days it goes under contract. 10 days into the contract is terminated because the parties couldn't reach agreement on inspection objections. The property goes back on the market for another 7 days before going back under contract, this time closing after another 30 days.
CDOM is Cumulative Days on Market... it only counts the time that a property was actually active, and in my opinion the best indicator for market activity. in the above case CDOM would be 12
DOM is total days from the time the property is listed until it is sold, in this case it would be 52.
Original to Sold price differential or ratio is calculated by dividing the final sold price by the original listing price.
A house is listed at $100,000 then sells for $95,000 The differential or ratio is 95%
Then it's always important to look at Median vs Average before you compare a set of numbers. Medians are the middle of a number set, while an average is all the numbers added up then divided by the number of data points. It seems semantic but the Average is much more susceptible to an outlier.
Check out my answer to another question to see the differences between the average and median on the same data set.