Looks like your example data is wrong. Without an explanation of the rules, this is as close as I could get:

SELECT x.*, y.productID

FROM

(SELECT xState

, MAX(Sales) AS MaxSales

FROM salesData

GROUP BY xState) X

INNER JOIN salesData Y ON X.xState=Y.xState

AND X.MaxSales=Y.Sales

Here's the result I got:

xStateMaxSalesproductID

Ap80P1

Mp70p2

Tn50p2