Final answer:
Player B has an 8.16% chance of drawing a seven from the remaining 49 cards in the deck to win the round after Player A's total reached 19.
Step-by-step explanation:
Probability of Player B Winning
Player A has an eight and a nine, totalling 17 points, and then draws a two, bringing their total to 19. Player B has a four and a jack, which totals 14 points.
For Player B to win, they must draw a card that brings their total to higher than 19 but not over 21. This means Player B can only win if they draw a seven, which gives them 21 points. Since there are four sevens in a standard 52-card deck and three cards have already been drawn without replacement, there are 49 cards left.
This simplifies to approximately \(0.0816\), or an 8.16% chance that Player B will win the round.