The number of times that an individual contracts a cold in a given year is a Poisson random variable with parameter equal to 3. Suppose that a new drug reduces the Poisson parameter to 2 for 75 percent of the population. For the other 25 percent of the population, the drug has no effect. Given that a random individual from the population tries the drug for the year and has 0 colds in that time, how likely is it that the drug was actually effective for this individual