Final answer:
The sum of the probabilities for having two dogs (0.4) or two cats (0.4) is 0.8. Since this is not an option provided, there may be an error in the question or given options. The probability for either event occurring separately is 0.4.
Step-by-step explanation:
The experimental probability that the family has two dogs or two cats can be calculated by using the marginal distribution data provided. The probability for dogs is 0.4 and for cats is also 0.4. To find the probability of the family having two dogs or two cats, we add these probabilities together because these events are mutually exclusive, meaning they cannot happen at the same time.
Therefore, the experimental probability is 0.4 (dogs) + 0.4 (cats) = 0.8. Since there is no option for 0.8 in the given choices (a) through (d), it seems there might be a mistake either in the provided options or in the interpretation of the question. However, if the question is asking for the probability of either event occurring separately, then either 0.4 for just dogs or just cats would be the answer, which is not listed among the options given.