# binomial probability.

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• Nov 19th 2011, 12:24 PM
foliocb
binomial probability.
Scenario: "during any semester at the local college, 42% of the students are taking a math course. Determine the probability that if 10 students are selected...:"

Question 1: That exactly 7 are taking a math course.

Question 2: Less than 3 students are taking a math course

Question 3: At least 3 students are taking a math course.
• Nov 19th 2011, 12:37 PM
Plato
Re: binomial probability... bleh
Quote:

Originally Posted by foliocb
Scenario: "during any semester at the local college, 42% of the students are taking a math course. Determine the probability that if 10 students are selected...:"

Question 1: That exactly 7 are taking a math course.

Question 2: Less than 3 students are taking a math course

Question 3: At least 3 students are taking a math course.

Binomial probability is \$\displaystyle \binom{N}{k}(p)^k(1-p)^{N-k}\$.

1) \$\displaystyle N=10~,~k=7,~\&~p=0.42\$.

2) Let \$\displaystyle k=0,~1,~2\$ add up.

3) subtract answer in 2) from 1.
• Nov 20th 2011, 12:09 AM
foliocb
Re: binomial probability... bleh
Ok, i got:

1) ~5.4%

2) My final answer was ~13.72% when I totaled the three up, first one I got ~10.17%, second got ~3.12% and third got ~.43%

3) came out to 100-13.72 so 86.28%

hope I got it right :s