ATAR Notes: Forum
VCE Stuff => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematics => Topic started by: Amith2002 on July 26, 2020, 08:34:21 pm
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Hey guys!
I'm trying to understand binomial probability and I have a past paper question that i'm trying to answer. The answer is 0.028, I got 0.0243...
The question goes:
In the past, ten percent of people who have been offered a scholarship to complete a particular tertiary course have been male. Of the three scholarships offered this year, what is the probability that less than two were offered to females?
I understand how to get p and n but the only difference is that they got 3C0 and I got 3C1 because they are asking for less than 2.
Help is much appreciated, thanks!
-
Hey guys!
I'm trying to understand binomial probability and I have a past paper question that i'm trying to answer. The answer is 0.028, I got 0.0243...
The question goes:
In the past, ten percent of people who have been offered a scholarship to complete a particular tertiary course have been male. Of the three scholarships offered this year, what is the probability that less than two were offered to females?
I understand how to get p and n but the only difference is that they got 3C0 and I got 3C1 because they are asking for less than 2.
Help is much appreciated, thanks!
The answer from the exam is right, because less than 2 implies that there are two outcomes that fit with the condition- either no women get the scholarship or 1 woman gets the scholarship.
So when calculating the probability, you should be adding both Pr(X=1) and Pr(X=0) to get the correct probability.
Also, you made a mistake in your calculations for Pr(X=1), because you didn’t do the formula correctly- it should be (9/10)^1, not (9/10)^2. It should also be (1/10)^2 instead.