And/or
- Thread starter Melissa79
- Start date
Hello, Melissa79!
To answer your question, he wants you to multiply on a tree diagram.
And suppose A happens (or doesn't happen) first, then B.
The tree diagram looks like this:
The far-left branch is: \(\displaystyle \;P(A \cap B)\,=\,\frac{2}{3}\,\cdot\,\frac{1}{4}\,=\,\frac{1}{6}\)
. . That is, the probability that A happens <u>and</u> B happens is \(\displaystyle \frac{1}{6}\).
The far-right branch is \(\displaystyle \;P(\~A \cap \~B)\,=\,\frac{1}{3}\,\cdot\,\frac{3}{4}\,=\,\frac{1}{4}\)
. . The probability that A does not happen <u>and</u> B does not happen is \(\displaystyle \frac{1}{4}\).
Reading down the branches, those are "and" statements . . . hence, we multiply.
To answer your question, he wants you to multiply on a tree diagram.
Suppose: \(\displaystyle \;P(A)\,=\,\frac{2}{3},\;P(B)\,=\,\frac{1}{4}\)
And suppose A happens (or doesn't happen) first, then B.
The tree diagram looks like this:
Code:
*
/ \
/ \
2/3 / \ 1/3
/ \
/ \
A ~A
/ \ / \
1/4/ \3/4 1/4/ \3/4
/ \ / \
B ~B B ~B. . That is, the probability that A happens <u>and</u> B happens is \(\displaystyle \frac{1}{6}\).
The far-right branch is \(\displaystyle \;P(\~A \cap \~B)\,=\,\frac{1}{3}\,\cdot\,\frac{3}{4}\,=\,\frac{1}{4}\)
. . The probability that A does not happen <u>and</u> B does not happen is \(\displaystyle \frac{1}{4}\).
Reading down the branches, those are "and" statements . . . hence, we multiply.
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- Feb 4, 2004
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Melissa79 said:
Denis said:
Melissa79 said:
Lizzie said:He gave you his opinion, lol.
Which? The tutor giving you intelligent advice ("To be sure what your instructor wants, ask him"), or the fellow student gently pointing out that you had received what you'd asked for?Melissa79 said:
While we may have opinions (some of which have been provided above) regarding what your instructor might have meant by what you interpret him as having said or implied, only he can clarify his meaning in accordance with how he plans to grade you.
Sometimes terminology is not fixed, or terms or statements in class are misheard or misinterpreted, or somebody uses a term oddly (or just plain incorrectly). Asking people other than your professor what your professor might mean by a statement he may have made might be an interesting endeavor, but asking the professor directly is, I think, still the best way to get the definite answer you seek.
I apologize for any offense.
Eliz.
Wow I did not think that me asking an (opinion) about something would be such a big deal. I appreciate the help I have received with my questions. I did ask my professor what he meant ,but he left it up to the students to figure it out. That is why I sought some help. I ONLY wanted some feedback.
In that case, all you had to do was say that you asked your professor and let us know what he said. It is NOT a big deal. We are just trying to help you, but we really need to know all of the information for the problems before we can help. We were just trying to make sure that you had given us all of the information. Trust me, many people only give pieces of problems and expect us to solve a partial problem! (Actually, I even did that a couple of times when I first started posting.) You would not be the first person to have done this. No one is being rude, at least not intentionally and we appologize that you see it as such. I personally promise not to say anything that you may consider to be rude. I will be more careful next time, just please understand what we are trying to accomplish here.