2006-06-22 08:20:01 · 10 answers · asked by oriental_dr 3 in Science & Mathematics ➔ Mathematics
The basic equation of probability is P(A)= Limit(NA/N) as N approaches infinity. Where
A is an event
NA is the number of occurrence of event A over a population sample N
N is the to total number of samples (N does not have to infinite but sufficiently large)
For example if a pole is taken of a population size of 1000 people by asking them the same question and 400 of them answered with “No” then P(“Yes”)=600/1000 and P(“No”)=400/1000
As soon as you asked a question and included “A or B” statement you have opened … No that is okay, just more info.
When A and B are two independent events then the probability that events A and B both occur is: P(A and B) = P(A) x P(B). The outcome of one toss of a coin is independent from your next toss.
When A and B are mutually exclusive, then the probability of A or B is simply:
P(A or B) = P(A) + P(B).
The outcome of one toss of a coin will yeld either heads (H) or tail (T) since both H and T are mutually exclusive.
I hope that helps
2006-06-22 08:25:09 · answer #1 · answered by Edward 7 · 8⤊ 0⤋
What is the probablity of the outcome being either A or B?
Example 6 of item A, 6 of item B, 6 of item C, 6 of item D all in a bag. You reach in a randomly draw one out. What is the probability the out come will be either A or B?
50%
2006-06-22 08:23:40 · answer #2 · answered by cirestan 6 · 0⤊ 0⤋
I concur with the fist answer, go to math.com.
The examples the first few posters posted fail to consider that A and B may not be independent events.
I would explain this concept to my teen daughter by stating what is the probability the next guy you meet will ask you out or is at least 6 feet tall. She would answer 0% at this time - such is the life of a teen girl when down - but she would eventually figure the answer:
P( A or B ) = [ P(A) + P(B)] - P(A and B)
Hope it helps.
A concerned dad
2006-06-22 08:55:30 · answer #3 · answered by oxnumbernine 1 · 0⤊ 0⤋
Given 2 events A and B with probabilities P(A) and P(B), P(either A or B) means the probability that either A occurs or B occurs at one given occurence. In effect this means:
P(either A or B) = P(A) + P(B)
2006-06-22 09:06:57 · answer #4 · answered by hackmaster_sk 3 · 0⤊ 0⤋
P is the probability function, that tells how big chance it is that the statement inside the parenthesis is true. In this case, P tells how often (in percent, or the average value of (A or B)) either A or B is true.
2006-06-22 08:34:56 · answer #5 · answered by User1 2 · 0⤊ 0⤋
It means to find the probablility that either event A or event B will occur.
2006-06-22 08:23:45 · answer #6 · answered by Don E 4 · 0⤊ 0⤋
P(A) means find the probability dat A will be da outcome. same thing with P(B)
2006-06-22 13:56:04 · answer #7 · answered by michie 2 · 0⤊ 0⤋
no remember what percentage activities you've, you pick to sum up the probabilities of each journey then subtract the completed overlaps. the following, P(A) or P(B) or %) = P(A) + P(B) + %) - P(A and B) - P(A and C) - P(B and C) - 2*P(A and B and C) be conscious, you pick to subtract P(A and B and C) two times because it became counted 3 cases, in P(A), P(B), and %). all the probabilities of two activities intersecting were in undemanding words counted two times, so in undemanding words pick to be subtracted once. ~Zara Sahana
2016-11-15 03:14:11 · answer #8 · answered by ? 4 · 0⤊ 0⤋
P(A) + P(B)
If they are mutually exclusive (i,e if they have nothing in common)
OR
P(A) + P(B) - P(A n B)
if they are collectively exhaustive.(i,e if they have something common)
2006-06-22 09:24:09 · answer #9 · answered by softlooking 1 · 0⤊ 0⤋
go to www.math.com
2006-06-22 08:23:18 · answer #10 · answered by houstonmom77064 3 · 0⤊ 1⤋