Math Probability: Question Help ME Please!!?
Please open up the link below:
and teach me how to do the questions you see there. I am stuck and don't know how to start.
Please SHOW steps & FINAL answer. Best ANSWER will be given out to anyone who helps me.
- MathMan TGLv 78 years agoFavorite Answer
If you ask 3 people, a yes/no question of any kind,
what are the possible numbers of "yes" responses ?
What's the fewest, if they all answer "no"?
What's the most, if they all answer "yes"?
Write down all possible sequences of 3 letters
consisting of only F and D.
Here's half of them:
I bet you can figure out the other four from there.
Then since Probability(F) + Probability(D) = 1
(since we assume there are no Martians included)
P(D) = 1 - P(F) = 1 - .27 = .73
Then P(some sequence of D's and F's) = individual probabilities multiplied together.
P(DFD) = .73 * .27 * .73 = .143
Substitute .73 for each D, and .27 for each F and multiply.
Shortcut: all the ones with the same letters in different orders come out the same.
Now if you have, for example, the sequence DFD,
that is 2 D's and 1 F, so the count W = 1 in this case (for the 1 F)
So you can
- make an 8 row table for all the possibilities
- and compute their probabilities
- and count the F's in each sequence
- and write that down on the side
- and then add up the probabilities for each count.
And you end up with this:
.... Probability... W
DDD 0.389017 0
DDF 0.143883 1
DFD 0.143883 1
DFF 0.053217 2
FDD 0.143883 1
FDF 0.053217 2
FFD 0.053217 2
FFF 0.019683 3
This is called a Binomial Distribution.