Clients Business Activity Analysis - building a Pivot Table or functions needed

[MatthieuM]

Hi everyone,

It’s been 6 years since the last time I had to run some basic statistics myself on Excel and I must say than I’m having some troubles with the following.

A little help would be very helpful. I just don’t expect you to do it for me. I would actually love to understand what I need to do to find these information myself later.

With this basic table -for which I'm attaching a replica to this message, I’m looking to answer the followings:
A. Run an analysis that will show from July 2018 to December 2018 [the business activity is calculated over a period of 6 months]
A.1 the number of active clients per month, with the % of new clients (as of July 2018 therefore) and existing clients (before July 18) per month
A.2 the number of new clients per month, with the percentage of active and inactive clients per month
A.3 the average number of purchase per active clients, per month

Regarding these first 3 points, I’m not sure which functions to use and if and how I can make a pivot table to help me do this analysis. What do you think? Is a pivot table an option? If so, would you mind walking me through?

And then, there’s these:
B. Run a cohort analysis from Sept 18 to Dec 18 to:
B.1 show the evolution of the % of clients who make at least a purchase within a month
B.2 show the evolution of the average number of purchases made within a month
The same holds true here. I’m not sure how to organise this so I can make a graphic. Or could I use the pivot table built for question A ?

I think it’s big help I’m asking here and I’m a bit embarrassed to do so but again your help would be invaluable as I’m trying to understand what I’m doing so I can do this by myself next time

Thanks