A straightforward question about organizing data in Excel

I am working with the data in the attached excel file. This is a stock that is traded on an exchange. There is price for every trade. A deal is comprised of several trades. I want to find the average price PER DEAL (I can do this), and then to form a new column where I have the average price PER DEAL for every trade WITHIN the deal. Thanks very much in advance!

I attach an updated file. Here you can see some of the results. If you look at deal 115, it consists of two trades: 156 and 157. Price is 68 for both, so the average is 68 also. Look also at trade 118, it consists again of two trades: trade 165 with price 67.95 and trade 166 with price 67.9. Here the average price is 67.925 and I want it for both trades as shown in the file

Cannot express my gratitude.....THANKS!

Can you help me with the final issue (again a very quick one I believe, but beyond my abilities). I attach the file. Basically what I need is to fill all the blanks between two values with the value above. I provide some examples in the file. Much appreciated!

For some reason Excel says : "No cells found" when I try to go to Special>Blanks>Ok. When I specified my columns, I used a formula and wrote "" for these cells in order to be blank, dont know if this might have an impact. Copying the columns to a new sheet (values only) does not make a difference

The formula I used is:
=IF(AND(L2=1,O2=1),R2,"")

Problem solved!