Averageif Formula average of 1 column based on another column if not blank

[weaselmcguff]

I have a spreadsheet in Column P i have a drop down of 11 different findings. In Column M i have a calculated time based on 2 other fields for when a truck
started to be loaded and when the truck was finished being loaded.

I am trying to calculate the average time it took to load a truck where based on the Column M values when Column P is not blank

attached is an image of the formula i am trying to use and the errors i get.

I want the entire column M and P to be part of the formula. Because some days we have 10 shipments other days there could be 150

Thanks for your assistance

 

[ExceLoki]

try this

=AVERAGEIF(P:P,"<>",M:M)