The probability that the favorite team of a randomly selected baseball fan is the Boston Red Sox can be found by dividing the number of Boston Red Sox fans by the total number of fans.
It's given that there are 12 Boston Red Sox fans and 18 other fans. Therefore the total number of fans is 12 + 18 = 30.
If we divide the number of Boston Red Sox fans by the total number of fans, we get 12/30 = 2/5. Finally, we have P(Boston Red Sox) = 2/5.
