Question

For a certain type of hay fever, Medicine H has a 30% probability of working.

In which distributions does the variable X have a binomial distribution?


Select each correct answer.

Answer 1

When the medicine is tried with two patients, X is the number of patients for whom the medicine worked.

When the medicine is tried with two patients, X is the number of doses each patient needs to take.

When the medicine is tried with six patients, X is the number of patients for whom the medicine worked.

When the medicine is tried with six patients, X is the number of patients for whom the medicine does not work.

Answer 2

can someone explain to me how to know which ones are a binomial distribution?

Answer 3

A binomial distribution depends on two parameters: the number of independent trials and the probability of success for each trial, where "success" is the keyword. The distribution is intended to give a measure of how likely it is for a trial to have a successful outcome.

The experiment in this case then has nothing to do with how many doses any one patient needs to take, but rather whether or not *any* dosage ultimately works, so you can eliminate the second option.

Because a binomial distribution revolves around successes, you can ignore the fourth option.

The takeaway here is that in order to identify if an experiment can be modeled with a particular distribution, you need to be able to identify what parameters are given to you and what you're trying to measure. Whenever you're given two possible outcomes (even as simple as something happening versus it not happening), a binomial distribution will likely be the right one.

Answer 4

Um...was this helpful?