SOLUTION: In a class of 35 students, 11 are seniors, 8 are juniors, 9 are sophomores, and 7 are freshmen. If two students are selected at random from this class of 35 students, find the prob

Algebra ->  Probability-and-statistics -> SOLUTION: In a class of 35 students, 11 are seniors, 8 are juniors, 9 are sophomores, and 7 are freshmen. If two students are selected at random from this class of 35 students, find the prob      Log On


   



Question 1160579: In a class of 35 students, 11 are seniors, 8 are juniors, 9 are sophomores, and 7 are freshmen. If two students are selected at random from this class of 35 students, find the probability that the first student selected is a junior and the second is a sophomore.[Give your answer to nearest 5 dp]
Answer by Theo(13342) About Me  (Show Source):
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in a class of 35 students.....,
11 are seniors, 8 are juniors, 9 are sophomores, 7 are freshmen.
two students are selected at random.
find the probability that the first student selected is a junior and the second student selected ia a sophomore.
the probability that the first student selected is a junior is 8/35.
the probability that the second student selected is a sophomore is 9/34.
the probability that the first student selected is a junior and the secont student selected is a sophomore is 8/35 * 9/34 = 72/1190 which can be simplified to 36/595.
in decimal form, that's equal to .06050 rounded to 5 decimal places.
this is an example of probability without replacement.
the first probbility has a total of 35 students as the denominator.
the second probability has a total of 34 students as the denominator, since one student was drawn from the universe and not replaced.