Tina Sierra investigated a fight outside a college classroom. At this college, 75 percent of the students are female and 25 percent are male. Bob, a witness, testified that a male started the fight. After testing, Tina determined that Bob correctly identifies a person's gender 90 percent of the time. Tina concluded that there was a 90 percent chance that a male started the fight. Her mistake is a(n)

Question

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Tina's mistake is a violation of base rates, which means she did not properly consider the prior probability of a male starting the fight, given that only 25 percent of the students are male. By relying solely on Bob's testimony, she ignored the fact that, even if Bob is accurate in his identification of gender, there is still only a 25 percent chance that a male was involved in the fight.

Tina Sierra Investigated a Fight Outside a College Classroom