Final answer:
The player's expected winnings per round in American roulette is -$0.474.
Step-by-step explanation:
The player's expected winnings can be calculated by finding the probability of winning and losing each round and multiplying it by the amount won or lost in each round. In this case, the player's bet is $9.00 on red. The probability of winning in American roulette is 18/38 (since there are 18 red numbers out of 38 total numbers). So the player's expected winnings per round can be calculated as:
Expected winnings = (Probability of winning * Amount won) + (Probability of losing * Amount lost)
= (18/38 * $9.00) + (20/38 * (-$9.00))
= -$0.474
Therefore, the player's expected winnings per round is -$0.474, which means the player can expect to lose approximately $0.474 per round.