Suppose the probability that a U S resident has traveled to Canada is 0.18 to Mexico is 0.09 and to both countries is 0.04. What is the probability that an American chosen at random has traveled together Canada or Mexico?
Let a U S resident travelling to Canada be an event A and to Mexico event B.
Corresponding probabilities are P(A) and P(B) respectively.
The probability that a U S resident travelling to both countries is given by P(A `nn` B).
We have to find the probability that an American chosen at random has travelled together to Canada or Mexico which is given by P(A `uu ` B).
Addition theorem of probability for two events states that “If A and B are two events associated with a random experiment, then P(A `uu` B) =P(A) + P(B) - P(A `nn` B).”
Putting the values:
P(A `uu` B) = 0.18+0.09-0.04
Therefore, the probability that an American chosen at random has travelled together Canada or Mexico is 0.23.