Answer:
According to information given, in the targeted cell we will use formula
=Average(data cells)
and for other part of question is to calculate sales. For this part we can simply use sum formula, first we will sum the sales for single product in past events column then at the end of past column we will apply
=Sum(data cells) or =Sum(C4:C89)
Above formula is just to give example. In this way we can calculate both answers.
