Question

A student studying for a vocabulary test knows the meanings of 12 words from a list of 24 words. If the test contains 10 words from the study list, what is the probability that at least 8 of the words on the test are words that the student knows? (Round your answer to three decimal places.)

Answer 1

http://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.355591.html Try that maybe.

Answer 2

P(8) + P(9) + P(10)

Answer 3

@sourwing How do I calculate this? I always mess these up

Answer 4

O_O...

Answer 5

IDK how to do this.

Answer 6

for \(P(x=8)\) the denominator will be the number of ways to choose 10 out of the 24 questions
the numerator will be the number of ways to choose 8 out of the 12 known, times the number of ways to choose 2 out of the 24 unknown

Answer 7

i had a typo above, i should have written \[the numerator will be the number of ways to choose 8 out of the 12 known, times the number of ways to choose 2 out of the 12 unknown

Answer 8

whole this is a typo
i must be tired
let me try again

Answer 9

\[P(x=8)=\frac{\binom{12}{8}\times \binom{12}{2}}{\binom{24}{10}}\]

Answer 10

that is better

Answer 11

\[P(x=9)=\frac{\binom{12}{9}\times \binom{12}{1}}{\binom{24}{10}}\]

Answer 12

Thank you!