A student dormitory in a college consists of the following: 30% are freshman of whom 10% own a car 40% are sophomore of whom 20% own a car 20% are juniors of whom 40% own a car 60% of seniors own a car A student is randomly selected from this dormitory. (a) What is the probability that this student is a senior? (b) If the student owns a car, find the probability that this student is a senior.
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Therefore, the probability that a randomly selected student is a senior is: $$ P(\text{Senior}) = 1 - P(\text{Freshman}) - P(\text{Sophomore}) - P(\text{Junior}) \\ = 1 - 0.30 - 0.40 - 0.20 \\ = 1 - 0.90 \\ = 0.10 $$ So, the probability that the student is a Show more…
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