What's the easiest way

I need to come up with a spreadsheet, instead of a database, that will allow
someone to enter

Salesman; Company Sold To; State the company is in; & The amount of pairs
the company bought.

I'm thinking Column A to be Salesman; Column B Companies; so forth...

What would be the easiest way, to show the percentage of overall pairs sold
to a certain state?

How about this

Where E1 is State your looking at. Also format cell with Formula to %

=SUMPRODUCT((--($C$2:$C$30=E1)*(D2:D30)/SUM(D2:D30)))

VBA Noob

I have tried it; I put that formula in E column;

Column A is my Salesman; Column B is the company sold to; Column C is the
state the company is in; Column D is the amt of pairs sold;

Then in E1 I have MI, being Michigan state; I copied that formula into E2;
and dragged it down. the ones below are showing #DIV/0 but that's because
there is no information in the corresponding cells, But I don't think it's
accurate

Nevermind, I got it.

I am using the formula =If($c2="MO", $d2, 0)
and putting that formula into Column F, then for another state put in in G,
and H and I

then at the bottom I will use another formula, to calculate the percentages.

Thank you.