Posted by **Antonio** on Monday, April 16, 2012 at 2:03pm.

If the probability that event A will happen is 1/4 and the probability of A not happening is 3/4, find the probability that event A happens 3 times out of 7 experiments

- Math Probability -
**MathMate**, Monday, April 16, 2012 at 3:23pm
A binomial distribution applies when

1. Trials have exactly two possible outcomes

2. probabilities remain constant throughout trials.

3. there is a defined number of trials.

4. trials are independent of each other.

5. the random variable is the number of successes.

Since the problem appears to satisfy all the requirements, we will use a binomial distribution to model the probabilities.

p=P(A)=1/4

q=1-P(A)=3/4

From (p+q)^7, we look for the term

P(3)

=(7,3)p^3*q^4

=(7!/(3!4!))(1/4)^3(3/4)^4

=2835/16384

## Answer this Question

## Related Questions

- Probability Math - Event A has probability of 0.2 and event B has probability ...
- Math - In an experiment, the probability of the event E is known to be .4. Also...
- math - when you find the probability of an event happening by subtracting the ...
- statistics - conditional probability - Event A has probability 0.9 of occurring...
- statistics - conditional probability - Event A has probability 0.9 of occurring...
- Statistics - Event A occurs with probability 0.1 and event B with probability 0....
- math-high school - If the probability of an event happening is 2/5, then the ...
- Geometry please help me need to finish! - 1.Who was Blaise Pascal and how did he...
- math - If the probability of an event happening is 2/5, then the probability of ...
- Math - If the probability of an event happening is 2/5, then the probability of...