A National Park Service survey of visitors to the Rocky Mountain region revealed that 50% visit Yellowstone Park, 40% visit the Tetons, and 35% visit both. 8. What is the probability a vacationer will visit at least one of these attractions

0.55 or 55%

Step-by-step explanation:

Let A represent the event when a vacationer visits Yellowstone Park

Let B be represent the event where a vacationer visits the Tetons.

We are told that 50% visit Yellowstone Park. Thus; P(A) = 50% = 0.5

Also,that 40% visit the Tetons. Thus;

P(B) = 40% = 0.4

Also that 35% visit both.

Thus; P(A & B) = 0.35

Now, probability that they visit at least one of these attractions will be P(A or B)

Now, formula for P(A or B) is;

P(A or B) = P(A) + P(B) - P(A & B)

Thus;

P(A or B) = 0.5 + 0.4 - 0.35

P(A or B) = 0.55

answer: group b.

step-by-step explanation: