Question

The number of times that a person contracts a cold in a given year is a poisson random variable with parameter λ = 5. suppose that a new wonder drug (based on large quantities of vitamin
c.has just been marketed that reduces the poisson parameter to λ = 3 for 75 percent of the population. for the other 25 percent of the population, the drug has no appreciable effect on colds. if an individual tries the drug for a year and has 2 colds in that time, how likely is it that the drug is beneficial for him or her?

Answer 1

It's not beneficial, at all.