Producing a Target-Lead-Opportunity-Deal planning Funnel using an Excel Chart.

I'm trying to create a visual representation in Excel, to mirror something I've been sent in Powerpoint. Essentially I want to produce a Partner Marketing Planning funnel, so if our Marketing person knows what the average deal size is from a given Partner company, they might plan to produce maybe 5 x Deals during a Quarter.
Based on some standard industry Percentages, what I'd like is for someone to plug in the Number 5 at the bottom of the funnel, for example, and formulas will calculate the other numbers all the way up....so 5 will be 20% of the number above...the Opportunities will be 50% of the number above....so by asking for 5 x Closed Deals, the funnel will produce a number of 6,720 'Targets' that the Partner would need to reach out to with their Marketing, in order to generate the desired number of closed deals.

So how close is it possible to get to the attached picture in Excel? Are there any non-standard Chart options which can get me pretty close?

Thank you in advance!

Wendy

Thank you Andy - that looks exactly like what I wanted. I suppose the only issue is that when real numbers are plugged in, the top of the funnel becomes massive, whilst the bottom as good as vanishes, but I think that can't be helped; any Excel chart would do the same thing.
I'm just trying to replicate what you did now.....so I've highlighted the data cells - I imagine you went to Insert -Shapes next. Then what?

Thank you!

Wendy