PROB

[tltdas]

Hi. Here is my question. :shock:

In a certain college, 33% of the physics majors belong to ethnic minorities. FInd the probability that from a random sample of 10 physics majors, no more than 6 belong to an ethnic group.
Would I use the formula- P(x)= C(n,x) p (to the x) q (to the n-x)

Also, would P be .33 or would it be 6/10, which is 3/5.

Thank you

 

[tkhunny]

In a certain college, 33% of the physics majors belong to ethnic minorities. FInd the probability that from a random sample of 10 physics majors, no more than 6 belong to an ethnic group.
Would I use the formula- P(x)= C(n,x) p (to the x) q (to the n-x)

You are in the right ballpark, but it appears you have confused yourself a bit.

The proportion of the population is 33%. This makes p = 0.33.
The number in your sample is 10. This makes n = 10.
The measurement of interest is "no more than 6". This makes x in {0,1,2,3,4,5,6}.

You must calculate all seven of those, or calculate for x in {7,8,9,10} and subtract from unity.

Pr(no more than 6} = 1 - Pr(7 or more)