I bought when the sign showed one amount, then the estimate online was higher before the draw. Does my ticket go with the final jackpot for that drawing, or the number advertised when I bought it? This seems obvious but I never saw it explained plain.
Your play is for the drawing printed on the ticket, not for the estimate shown at the moment of purchase. If the estimate rises before that draw because sales are stronger than expected, every jackpot-winning play in that drawing shares the same final jackpot calculation under the game rules.
The key word is estimate. Powerball says both the advertised annuity and cash value remain estimates until ticket sales are final; the annuity also depends on funding bids. The result page may therefore show a final amount different from the shop sign. The issuing lottery must still validate any ticket and claim.