Final answer:
The probability that a randomly selected dog from the dog park is a beagle is 1/2, as there are 5 beagles out of 10 dogs in total.
Step-by-step explanation:
The question is about finding the probability that a randomly selected dog from the dog park is a beagle, given that there are 10 dogs in total and 5 of them are beagles. To calculate this probability, we use the formula P(Event) = Number of favorable outcomes / Total number of outcomes. In this case, the number of favorable outcomes (beagles) is 5, and the total number of dogs is 10. Therefore, the probability, written as a fraction, is 5/10. This fraction can be simplified to 1/2, which corresponds to answer choice a) 1/2.