# Thread: binomial probability.

1. ## 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.

2. ## Re: binomial probability... bleh

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.

3. ## 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